For a good start, you should complete the newbie tour offered, when you have created a new character. You should learn how to dress and undress, change your shape, how to use "attachments" (accessories like hair, belts, handcuffs that tie you up, etc.) and learn some basic building. You do not have to do this, but it will help you later on. Also get a free "ZHAO", which is a device that makes your movements a lot nicer - attention, this is gender-specific. The original movements of SL make you look as good as a badly drawn cartoon character. You should also get a "RLV relay". This is a cool attachment that exposes you to RLV (restrained love) devices and they are available for free.
Here are some links to interesting places. If you have SL installed, clicking on a link should start SL and once you have logged in, you should find yourself in the location of that link.
http://maps.secondlife.com/secondlife/Ga...e/25/13/22
Sin Labs & Club Circe - a large area dedicated to BDSM, many shops, a discotheque with real parties, a racing track with special motorbikes - watch for yourself.
http://maps.secondlife.com/secondlife/Li.../80/160/76 Little Shop of Kink - exactly what it says, except, there are many shops. There is a large area for playing and stuff as well. My recommendation there: Look for a shop with a sign "Real Restraint". In my opinion, the best ropeworks available in SL, called "Shibari Arms" and "Shibari Legs". The seller is the inventor of the "Restrained Love Viewer", Marine Kelley.
http://maps.secondlife.com/secondlife/Ga...e/25/13/22 Shop Makiko, has some demo versions of bondage toys and a few other surprises. Walk around the area, there are two or three shops and some playgrounds.
more places:
http://maps.secondlife.com/secondlife/Fr.../38/149/39
http://maps.secondlife.com/secondlife/No...247/140/56
Searching for places with keywords like "BDSM", "bondage", "latex" and the like will show you many more places. You will be offered to join groups. Do read the group descriptions first, make sure that they do not charge money for membership (they hardly ever do that though). If it seems interesting, join. You can always leave a group. The group tag will show to others. You can select, which group tag is "active". If you want to go to a "normal" area, best don't have a group active with a name like "fucking the day away". 😉
Some shops offer free clothes and also bondage toys. 90% of that is junk, but among the remaining 10%, you can find real nice stuff. Also look for "Gift Chairs", big chairs with a letter on display, giving a gift to the first sitter whose name begins with the letter. There are also games and "treasure hunts" where you can win items and clothes. Look around for "The Big Box of Dari's Junk". This is the legacy of someone who sold BDSM stuff in the past but left SL. It is absolutely free, do not pay a single Linden-Dollar for it, rather search on.
There are many more places, use search to find them. Also find a sandbox where you can familiarise yourself with "building". Building is not important for BDSM in SL, but you should have some ideas for readjusting ropes and other stuff.
As for BDSM and other sex equipment, there is a lot more than the shibari ropes. There are various restraints, machines and other stuff. You will discover a lot while exploring the above links. Many devices can be tested in shops for free. Some shops also have traps, which can capture you if you are wearing your RLV-relay and have it activated. Capturing is usually limited to a certain time, but if you get bored, you can always log out of the special viewer, then log onto the standard viewer and move to another location. This should make the relay forget that you are trapped, and next time, be more careful or switch your relay to "off" or "ask".
Now, how to use bondage items? I will tell you with an example from dari's junkbox, the loking binder, which is an armbinder. First, find a place where you are allowed to "build". you can build at Little Shop of Kink or Sin Labs, I think. Find the box in your inventory, pull it from there onto the floor. Then right-click it on the floor - open - copy to inventory. The original box will remain in your inventory, you can always get the contents again. There will be a new folder in your inventory, find the box labelled "Dari's House Locking Binder v1 (boxed)", do the same with it to get its contents. Find that in your inventory again. Sorry, this seems complicated, but this is as complicated as it gets for now. Right click "locking binder" and "wear". Your avatar will now wear the binder, arms behind, just like the real thing. Close your inventory. Cool? Wait! Click the binder on your avatar. Click "help", then confirm the offer to give you a notecard. From here, you can simply read the notecard and learn by yourself. Alternatively, read on, but you won't get all the details.
Click the armbinder again, then click "lock". This will lock the armbinder and - if you are using the RLV viewer, make it "unattachable". You cannot detach it unless you unlock it first - from the same menu. Now, click "timelock", select "add 5 Min" for a start. Click "unlock" again. This time, the binder refuses to unlock, with a little message. You have to wait 5 minutes. At this time, be glad, you didn't click "one week". You can add more time if you feel like. Let's be daring and add 6 months! (!!!). Er, six months in this binder, without having tried anything else? No way! Relog onto the normal viewer. Then right-click the binder and select "edit". "edit" might appear after a few seconds only, but it will. In the "build" menu on top of the screen, find "scripts" and there click "reset scripts". Wait, until this process is done, it can take a minute. you can close the "build" window a
eady. When the progress window says "done", close it. Now click the binder, it is back to normal. This will work with pretty much every bondage item that has to be worn by an avatar. Now you can explore the menu without any real danger - or read the manual - or both.
The RLV relay (also available with similar names) can be reset just like any other scripted item: When worn, it is shown on your screen, right-click it, select edit, then open the build menu on top of your screen, select "scripts" and "reset scripts". All this does work well in the normal viewer and is often disabled in the RLV viewer.
Besides the RLV viewer, which I consider essential for BDSM and self-play, you might be interested in other erotic stuff. There is an "excite" system, which makes your avatar show arousal, makes poses and stuff, even moan and scream, when appropriate. I never tried it, it costs quite some money, but it seems to be cool.
I really encourage you to make friends in SL. Also check the group chats if you need help. Be decent and friendly and you should be treated the same. You can delete friends from your list and they won't find you again except by accident. While SL offers a lot of possibilities by itself, people are the real asset of this place. You will discover much more when you are social. But do not hesitate to say "no" if you mean "no".
OK, this was a long text, should get you started. If you have questions, post them here. If I fail to answer, feel free to send me a private message, perhaps I didn't see it.
An important landmark that I forgot:
http://maps.secondlife.com/secondlife/Gallii/105/86/33 a giant freebie store.