Can some Adults give me advice on my lack of confidence?

It's performance anxiety, and eventually you'll overcome it. If you learn to relax in those situations, you'll both enjoy them much more. There's nothing to fear, especially if you trust the guy.

If you're unsure about what to do, ask him what sort of things he likes. The alternative is to just "go for it" and read his reactions to what you're doing, which will show you what he likes the most without having to ask.

Firstly, be honest. This always helps diffuse frustration, trust me. Just be yourself. Tell your new BF something like "I find you so attractive, but I am kinda new to this. I want to please you, and I want to have fun. Would you please teach me what you like?"

Don't ever be afraid to ask a guy this.... we have it written into our hard-wiring to give a lady deference. If your beau is any kind of a gentleman, he will take you (gently) into hand. If not, than forget him. There are plenty of men out there your age, who WOULD accommodate you.

Trust me when I tell you this, because my wife was in your situation 10 years ago. And now, she's a sex-Frankenstein. She needs it like 5 to 6 times per week!

Hey doll, I just turned twenty yesterday! Sounds like you just have a mental block. If your boyfriend really placed importance on the physical stuff, he wouldn't be boyfriend material. The fact that he's your boyfriend means he's into YOU, not how experienced you are.

The key to any physical part of a relationship is communication. Sounds goofy and hokey, but trust me, it works. Let him tell you what he wants, and you tell him what you want. Be open to learning. If it's experience you want, you won't get it by freezing !

(Another piece of advice: read Cosmo. They sorta kinda know what they're talking about ;] )

Good luck!

Well the advice you can get depends on why you're lacking confidence...
If you're lacking confidence because you feel you're incapable of pleasing him, then my advice to you is to just try something and see how good it feels! If you're lacking experience or whatever just ask him what he would like to try tonight, then have a drink or two and go for it! :)
I know this may sound like crap advice, but if you try something sex-wise and it turns out to be amazing, I know that I'm so caught up in enjoying it that personally my fears and insecurities just disappear.
Hope I helped in some way!