Replying to Canon vs yongnuo

So, I'm thinking about buying a new lens. My choices of lens would be the Canon 18-55, the Canon 50mm f/1.8 and the yongnuo 50mm 1.8. Im buying a new lens for a few reasons. The 18-55 I want to buy for vlogging. I'm trying to start a blog. I also want to do a little skiing videography. I'm also trying to start doing some paid work in photography (portraits mostly), which is why I want one of the 50mm lenses. I already have a Canon 28-80 (broken auto focus) and a Canon 75-300 for skiing and other sports photography. If you were in my position, what would you buy?