How can I be more brave and have courage?

I'm kinda wimpy and everyone keeps telling me to grow a pair. Truth is, my dad is also kinda wimpy/not brave (no offense to him) so I think it could be genetic. I'm not only wimpy, I'm also very shy and people scare me / freak me out. I avoid people and be by myself. How can I be more courageous as the world is a very tough place?