advice from people who have lost their virginity

Question to those who have been in this subreddit for a while, but have now lost their virginity and are a bit more experienced:

What practical advice would you give those that are about to lose their virginity in their 30s/40s?

I’m scared that I could do something that the other doesn’t like (or NOT do something that the other likes). Yeah, I know people say communication is important, but what if there are obvious things you “should” know at that age but you don’t? I’d feel so embarrassed.