How do men learn to be manly?

How do men learn all the handy stuff? My boyfriend didn’t grow up fixing stuff or working on cars or anything. He’s trying to learn handy stuff so he can get things done without having to call other people. Everytime he takes on a project it usually doesn’t go as he expects and he losses all confidence in himself to be competent in fixing things. I feel bad and want to help him but I don’t really understand how guys learn how to fix things. Is it all learned when y’all are young or can you gain those skills?