I'm SO shy around guys? I need help?

So I'm 14 year old girl- I've always hated myself for being shy around guys, but today somthing happened that really mad me frustrated with myself. I was at the pool with my friend and two guys we knew walked by.. (they're reeeeally hot.) so my friend said hi to them, they both said "hi (friends name)!" and gave her a high-five.. I just sat there like an idiot.. And it really made me mad I didnt say anything or they didn't say anything. I don't know. Maybe I'm just a loser.. Any advice? Thanks!