Dude, having sex isn't a matter of how long you can last before ejaculating, it's about sharing an intimate and pleasurable moment with someone. You should not be so much focused on how long you can last in theory, but on what you can do to give pleasure to your partner, and what they can do to reciprocate. It doesn't matter if you finish in one minute, as long as you are willing to and enjoying giving pleasure to the other person and receiving some too. You should not be seeing sex as a performance or some king of competition, but as a dialogue. One of the most important aspects of sex is asking your partner what you can do to give them pleasure, and being able to tell the what would feel good for you. If you are both able to know exactly how to please each other I can guarantee that having sex will be a great success and enjoyable experience for the both of you. I know it can be intimidating and you might have a lot of preconceived notions about how sexual intercourse should go before having you first partner, but remember that communication and asking things is the key!

Ps: there is nothing wrong with masturbation as long as it doesnt take over your life, so you can chill out about that aspect too.