IMO, beginners don't meet real entities in the beginning. Especially not on the first time. But anyway, nothing can harm you in the astral! physically, you will still be fine. Nothing will happen to your physical body. You will go out of the body and come back good as new! and I trust that you will tell us how it was. But you'll have to try first. From my experience, you always can ask others, but the answer that will sound good to you must come from the inside, from your own being.

So start practicing so you can go OOB and find your own answers. That way you will be able to tell them to people in the future who will ask!

I advise that a quote you should always keep in mind is:
"Life is either a daring adventure or nothing!"
-Helen Keller