New boyfriend, new sex 😬

I haven't had sex in MONTHS. I have a new boyfriend, I'm 18, he's 21 and we've been together for a bit now, & we're supposed to be doing the deed soon. 😂 its been so long, that I'm so nervous and feel like its my first time again. He'll also only be the 3rd person I've been with so I'm still not "pro" at anything. Any tips? I feel like I've lost any knowledge that I did have! 😂 tia 😁