I never have anything to say to anybody?

Whenever people are talking I have nothing to offer. I feel like everybody has passions and knows more than me. Nothing is going on in my head in a conversation. I think it could be that I don't really have any interests I want to talk about but people seem to make jokes and conversation out of menial stuff like the weather and have a laugh whilst I can't. Whenever I get friendly with people it just ends up being me following them around and they eventually get bored because I say nothing. It makes me bitter when I see guys talk to girls I like, making them laugh and connecting. It's like nobody told them it's the hardest thing in the world. I've pretty much always been this way and have and have had very few close friends my whole life. It's a vicious cycle and dampens my social life so much I can't ever get any experiences to talk about. Has anybody been through this? I am 19 now and it sucks.