What is the AVERAGE number of Go-Around's a Student Pilot will attempt to complete a Landing?
A student is taught to go-around because it is safer than trying to fix a screwed up landing. In some cases an instructor wiill teach the student to fly the approach and then go around rather than attempt a landing. The object being to teach a good approach and not worry about the landing until the approach is at an acceptable standard. A good landing requires a good approach. As to the numbers, I doubt that anyone counts them.
Second Question, Do they always "get it right"?
Get what right, the landing or the go-around? Landings No; Go-arounds, mostly Yes, you only get one attempt!