Just find someone to help you pick the right size, get a cheap boat and go paddling. You'll soon see what you like about it and what would you change. Then wear it out and get one that fits you based on the experience with the first one.
This is how I found what boat would fit me the best: I started on traditional open canoe, then bought an old slalom C1 for urban fun and one-day ww trips. I found that my next open boat will have to be light, with lightly arched bottom shaped similar to older slalom boats (should slip sideways at will, no rails but some edges), quite long (I need speed and room for my guitar) and with enough rocker; tumblehome amidships, not too much volume in the ends (piercing waves and shedding them to sides rather than lifting the bow and jumping off them). I don't know if a boat like that exists but these are properties I like. The open boat I have used so far is fast enough for me, has the right amount of tumblehome, lifts the bow just the right way when piercing a wave, but it is heavy, the bottom is too flat, it has too little rocker and the ends are too low. The slalom C1 taught me what hull shape suits my needs, the open canoe showed me what I like or dislike further above the waterline. I haven't still outgrown the open boat I have used so far, I still can learn much more with it, but if I was to buy a new one, I already know what it would be like.
It's like cooking a new, unknown meal - the second attempt will be good but first you need to cook it and taste it to know how to do it really good or next time. Or like women - only those very lucky or very desperate marry the first girl they get interested in. The others try and learn.
As for the playboat, my roommate wanted to start kayaking. He got a used playboat, mostly because it was cheap and did fit inside his car. He successfully learned the basics, although it was a bit harder than in for example a slalom kayak, and now he enjoys playing on artificial slalom course in Prague. He also learned that this boat is too small and too slow for him (more so after he borrowed my 4-meter C1
) but he likes the edges and the shape of its bottom, so his next one will be a bigger playboat.
The moral of the story: Any boat will do, you will build experience and skills in any boat. By the time you learn enough to feel the limitations of the boat, you will have enough experience to choose a boat that fits all your needs.