How can tell the difference between hair bump and genital warts?

It's not easy if you are not experienced. The best advise is to visit a dermatologist

Usually a wart is solid, if you check on it closely, and you see there's nothing "inside" and it's 100% solid (just pure white solid thingey) then it is a wart. a hair bump/bacterial from shaving or masturbation infection/just some random bump usually won't look like this.

Also, a wart cannot be popped out while other bumps can. However, i dont recommend you to try to pop it out, just go to a dermatologist to make sure.