How can I make a lot of good friends?

Every time i meet someone, they think im annoying. Then, if they are really---lly nice people, they will still talk to me and then become a temporary friend. I don't want to "change who i am" but change how I act. I do realize that I sometimes act annoying and then most people judge me right off the bat and then avoid me. I am always the last one picked (if picked at all, which happens a lot) to sit at someone's lunch table. I am a little chunky, but I am doing colorguard this summer and also going to work out some. And I know that it doesn't matter what I look like, but i would feel more confident about myself... And any friend that I get, they either move, or we stop being friends. I feel when I say "bye" no one cares if I leave or stay, because they look at me then look away saying nothing...Please help me make a lot of good friends who will like my first impression. (PS. I'm not that shy)(PPS. I'm going into highschool in august)