I am really shy aimproveent. What should I do?nd I dont know what to do.?

I dont really have any friends, and the friends I do have im not that close to. I really dont know what to say in a group setting. I feel like everyone else knows what to say but I dont. I want to go up to people and say Hi, but for some reason i am always too nervous to do so and I back out. Since I dont talk much, I tink I give people the impression that I dont want to talk to them. I have been trying to change for the last seeral years but I have made little