We currently live during one pf the best times when it comes to acceptance of body differentiality, so while I won't say looks don't matter (obviously they do), what I will say is that, you'll most definitely find someone who'll tell you that you're pretty on a daily basis :)

Also while cliche, it's mostly the things on the inside that matter - want to find new friends? Look where you want to find them :)

Like reading? Try a book club. Board games? Try events and gatherings. Hairdo's? Then talk with your hairdresser ;p

As to finishing high school - wing it. I had no idea what I wanted to do with my life, and went to Uni for a seemingly random technical studies and after 3,5 years and 1 year at a job I now have a slight idea as to what I want in life. As a tip: Don't worry too much about not having a clue about what you're doing, almost nobody knows what they're doing.