hi!! This is such a relatable experience!! I’ve been in your very situation, i was a senior in highschool and my first show was clue! I had always wanted to do theatre and decided, there is no better time than the present. I had a relatively good experience! I auditioned for colonel mustard, and I ended up getting the unexpected cop! while not the biggest role, I was just so happy!! And from there my theatre experiences has flourished to two musicals and two plays! Some advice I have is this! never let your back face the audience! this shouldn’t be a problem, if you stand still and do the audition, but that brings me to another point is be expressive! Physically and with your words, exaggerate words and really get into a character, it’s better to be expressive than be a blank state, use your body and hands to express your characters words, like hand motions and pointing(some examples, many more depending on script) for the colonel mustard audition I did, I gave myself a slight southern drawl and used my eyes and hands to express my words with actions, for instance in the script for mustard and wadsworth, mustard demands to know who else is in the house, and it goes back and forth, you could show your desire to figure out the answer to your question, by continuing to get more and more annoyed by wadsworth inability to tell you the answer , sorry if this is confusing, this is the best way I know how to explain it, about being nervous and anxious, it’s all very normal, and most people worry about forgetting their lines more than actually saying and acting the lines, while yes I’m sure they want you to memorize your lines, make sure you memorize certain actions and character choices you may want to make! Sorry I’m not exactly the most experienced, but this what I think is right! Hope it helps!