What should I do about all this?

So i'm trying out for quarterback for my highschool. Last year I tore my ACL and obviously couldn't play. Now I'm going to be a sopre and I'm trying out. So we have had 2 days of practice. I don't know anything out of the playbook while the other 4 quarterbacks do because they have played before. I was a quarterback before this for a town team and had mastered that offense... but the highschool uses a completely different offense. Now... becuase I don't know the plays at all or anything I basically watch what the quarterbacks do that go before me and try to do that. But obviously my footwork is totally off because I have no experience with these plays and sometimes I miss the hand off. The coach started saying things like "Tough day at the office"... and (while smiling) "This is guna be tough for the new kid".. Now i'm trying. It's only been two days at practice. He released part of the playbook.. but not the actual plays. I have read that... but can't get it down without experience. I feel so dumb when I make a mistake and all the kids laugh and the coach says "tough day at the office" or something. I didn't play last year and this is all new to me. What do i do? Is this fair?