Gathering enough courage to talk to a girl..

Alright... So this is the longest streak I ever had. Previously I had social anxiety and I feared talking in a slightly large group. However, With some trying now I gather enough courage to talk infront of a group(of boys only). I go to a school which has boys only and thus am not exposed to much girls. But these days I have my exams going and am giving exams at a different place with many girls.

I always wanted to be confident enough to talk to a girl without any hesitation but in reality, I can't even go near them, I just start sweating and my heart starts racing.

So I was thinking if you guys could give me a tip to gather enough courage to step up..and talk to a girl confidently with a broad grin.

My aim is not getting a girl friend right now but to just gather confidence and talk to those of opposite gender...I believe you know what I mean.