You need to learn to dress
And I don't fucking mean put on a fedora and pretend you got swag or some shit like retards in /fa/ do.
I actually met people like that and they were pretty pretentious, and it did nothing to improve their image.
The best simple tips for learning to dress are this:
Buy clothes in your size. Your correct size. A lot of guys buy clothes one size too big and they look like they are wearing a tent or some shit.
Google clothe sizes and a chart somewhere will tell you what size chest and waist corresponds to shirt sizes, etc. If you're in a store, you try on a shirt and the shoulders should sit level on yours.
Same for pants, etc. If you do buy pants, whatever they may be, and they are too long or whatever then have them tailored to fit you.
If something doesn't fit you, don't buy it even if whatever X person in a movie or some shit recommended to you wears it
Grooming yourself is easy: Get a haircut at least once every one or two months, and make sure it is something simple. Different hair has different styles, ask the hairdresser what they think will suit you.
Facial hair is never done correctly except by some lucky people. No beard, especially neckbeards, or moustaches. Especially if you can't even grow one properly.
Get a shaver, learn to shave every day. Also wash your face every morning, if you have acne or whatever then go to a GP and get whatever creams or moisturisers you need to clear that shit up.