At this point your entertainer should have arrived and is setup and ready to go. Some performers have special requirements for their setups and you will want to ask what they will need.
If you have hired me (thank you!) I will generally arrive at least 15 minutes before Show Time and my setup happens in 5 minutes or less. Your guests can enter the space and start settling in before I even finish setting up.
It is very important to have at least a 30 minute buffer from the start of your party and the start of your entertainment. Most performers, including myself run a very tight schedule. We will have to start and finish on time in order to be on time for our next event.