hey hun, i teach trapeze and i'm sure your first class will be a blast!
where are you learning? who with?
your first class will probs just deal with conditioning etc, like wild card kitty said, your arms will knack but piking isn't an issue.
If you are really concerned about be unable to pike up, ask your teacher to show you how to 'beat' which encourages momentum. Thats what i do when I'm feeling less strong.
i actually hated my first trapeze lesson so don't place too much importance on that first class... the strength and confidence will come in time...
have fun
vicxx