Aloha everyone!

I'm finishing my 1st trainer. Just wanted to make sure I'm able to use any open channel not being used on my receiver for my switch? I have a Futaba 7cap tx. Can anyone help?

I want to fly my plane on Sunday (Father's Day) to surprise my husband, I actually put together my own plane to fly.... Wish me luck....

Any help or words of encouragement would be greatly appreciated!!!