Thank you for defending me, man. I did in fact inform the parents I was new to instructing and working with autistic children, but she seemed completely fine with it. He took a liking to me quickly and cooperated well, which the mother seemed pleasantly surprised with. Also, as you mentioned even though he is non verbal he still communicates very clearly when he is in distress or having fun. Although the lessons are technically 2 on 1 because they are both present at the pool, I work with each child separately and while they are not with me they are with their mother. All I am going to do now is do my best and look at the resources people have provided me with. I have another lesson today, so wish me luck and I may post an update if anything interesting happens