Sparring is all about learning. Not about seeing if you can knock that guy out or not. So, they will surely take is easy on you, because there would be no reason for them to take you on seriously. Especially, if they are all amatuer and pro fighters, because they know whats going on. There not going to have anything to prove to you so their just going to play around with you. Another aspect of sparring will also show your desire and heart. Your first time will show a lot. It will show your trainer if you have got the heart he is probably hoping you have. Relaxtion is key.