The water is over 60 degrees now. You have the option of wearing a dry suit or whatever you wish. Maybe neoprene. Bring a wind jacket in case you capsize or want to get wet. Air that day is around 60 degrees too. On this trip we are going to practice some strokes, towing, etc. You can also relax, and just paddle forward.
Dress to get wet, bring water, a snack, etc. Avoid jeans or other heavy cotton clothing.