It sounds like it’s your first time live firing. Don’t Panic™️.
I’d encourage you to have a word with staff when you arrive tomorrow. I’m sure they’ll be more than happy to give you a quick refresher, and will be pleased you’ve spoken up rather than fumbling around like many who’ve forgotten do.
If you’re a first time firer you should have 1-to-1 supervision from a coach / safety supervisor. As the name suggests, they’re there for everyone’s safety and to help you become a better shot. They’ll give you guidance where necessary, and ensure that you fully understand each practice.
Listen carefully to the Range Conducting Officer’s brief. They can be somewhat wordy, but they are important. Ask questions. Remember the basics - keep your finger off the trigger (except when operating it!), the rifle pointing down the range all the while, and pop the safety catch on when you open the bolt during drills.
Go along and give it a go. If you shoot one practice and decide it’s not for you, say so. But try it once. “Do one thing each day that scares you”.