Problem with my pennis and Sex Life?

So i am 21yrs old and i just recently fucked someone that was my first time.
I felt really good but the problem is that i was not that hard and that made it a little difficult to put it in ,but after so many attempt it worked.The a second problem as soon it went in after a 1min. i came i felt good but it didn't last to long why??

Please advice what do i need to do?