A big Congrats Nathan!!
First things first - you can’t roll without thigh straps or something else to keep you attached to the boat (you could also use braces).
As for what to do. I would recommend blowing it up and sitting in it while watching TV, lounging around, giving it the odd hug and caress. After that I would head out to those lakes and then to the sea. I am a massive fan of beach packrafting, as around here at least (Sydney), the water stays warm long into winter, rocks aren’t too much of an issue and pushing through solid waves is excellent training.