Costumes for Halloween?

Are there places to find female costumes for halloween for men? Also, what are some ways to look female for Halloween?

[Like Ra]

There is nothing easier: costumes for Halloween to look like a girl 😉

I'd approach this from the other end, decide on a look you like and then buy/put together the costume.

I looked at glamour boutique and bought some stuff. I have to retry, because the clothes and wig are too small. They don't do returns on wigs or sealed items.

Perhaps you should look for "crossdressing costume" (perhaps in your own language too). Most of the results I got are pretty horrible, i.e. quite suitable for halloween 😁
"sissy" is a good search tag too.
Once you are starting to get results, read the size charts and compare with your measurements.
And think about visible body parts vs. shaving. You probably want to look shocking rather than embarassing...

Well I got a dress that has long sleeves with it. Don't know if I will go out with it on, because I don't know any places that are lgbtq in my area. It probably wouldn't be too noticeable if I shave my legs because I usually wear pants.

[Like Ra]

if I shave my legs

Shaved (preferably epilated) legs look&feel much better anyway, regardless the clothes.