If you have the money for it, take a 3 day class
if you dont have money, no problem then you learn how the rest of us learned. it will just take a bit longer to enjoy being on class 3 rivers and you will have some valuable rescue and swimming experience:
Buy some cheap gear, join a club, do every club "learn to kayak" weekend you can, go to pol sessions, at the end of year 2, throw away/sell cheap to another beginner most of your gear and buy new used gear that is better [by then you will know better what you want].
Somewhere along the way take a rescue clinic at your club. For gear, I strongly urge getting airbags for whatever boat you buy. It will seem outrageously expensive but get them anyway. Get a new kayak helmet that fits your head and get a decent paddle. Go cheap on the first boat.