There's sort of a why-what-how series of questions that come into play during an internal conversation (a conversation with yourself).
For the "why" aspect, you have to sort out whether you want this for you (curiosity, excitement, whatever) or you are being driven by a desire to please someone else (aka "boyfriend thinks it would be hot!") . Put simply, if the interest/desire is not coming from within you,just stop. No one determines your sexuality except you.
For the "what" aspect, you need to sort out what you want the (first) experience to be like. What does that intimate episode look like in your fantasy? Is it anonymous or is there a relationship underpinning the experience? With whom? Having answered that question, what is fueling the anxiety? That you will be judged? That you might not enjoy it? That you might be hurt? Talking it out (to yourself) can be helpful.
If you made it to "how", that's a little easier. Person(s), time, place, boundaries, safety. And give yourself permission to back out at any time without fear of disappointing anyone--first and foremost yourself.
Good luck.