I usually look disheveled and dumb.? And I SUCK at socialisation that I come off as rude and a douche. Someone help me.

School just started and I want to make new friends, good ones. Importantly I don’t want to be in a hotspot with my teachers and I don’t want to give a wrong impression. How do I attract good people/energy? I really just want to be positive. My body language says otherwise tho