So I am not sure if this is the right subreddit for this kind of question but can't hurt to try.

TL:DR: How do I know my right condom size.

So currently I am a virgin and in a few days my 2 years anniversary with my GF. We are both free that day and her parents are out on vacation so we thought it would be a good day to enjoy our first time after a nice dinner date.

I'm not going to lie I am quite nervous for it.

I have never bought a condom before and really don't want to buy 5 different types of condoms to try which one fits if I don't need to.

So my question is how can I know which condom will fit me.

Also any help to make it enjoyable and less akward for us both would be nice.