Cosplay questions coming from a beginner

First is buying the costume bad if you can't sew nor anyone you know? Second do you have to wear a wig or can you use your normal hair? Also open to any random advice about cosplaying

Buying your costume is not really a bad thing, but be careful what you buy because some of those have horrible quality. Some might disagree and would say that you must make it, but cosplay is really about being a character you adore, not necessarily make the costume. There's a feeling of achievement when you do make your costume, homever. You can use your real hair or a wig as you wish. I do both depending on which character. The wig have the advantage of being quick. Meanwhile your real hair need to grow, being dyed (if needed), stylized, etc. so it's really up to you. As advice I'd say have fun. Also if it's not already done, learn to differentiate constructive criticism from people that are just being dicks.

Do what you want, have fun, be jolly, don't care about anything at all. That's how it works. Also, your costume is only bad if you think it is, some others might judge you but then they don't really belong at a convention. Buying is never a thing.

There is no rule against buying a costume. But, I find in the world of Cosplay your costume will look a lot better if you make it yourself. Effort can be seen but maybe that's cause I sew. No rules about using your own hair, but it will be difficult for you if the character's hair color isn't the same as your own. If you do use your own hair make sure it isn't done sloppily or anything like that, once again Cosplay has no rules and you can do whatever you want, but if your hair doesn't look right people won't know what you are cosplaying. Have fun regardless and if you do a great job, expect to be asked to pose. People will show their appreciation for your Cosplay by taking photos. It's exhausting after a long day, but believe me, seeing the joyful and excited expressions of the people that know your character or just love your Cosplay will give you a lot of gratification.

if youre a casual cosplayer and are in it soley for fun, there's nothing wrong with buying your costume and using your hair! i find wigs 1000 times easier than real hair once i got used to them. i prefer seeing homemade costumes because i like seeing people solving problems in fabric! (it gets easier sewing the more you do it, i essentially taught myself :P)