Hi, welcome to the forum
I'd recomend a RYA Powerboat two course. they are great value, great fun and give you good basic understanding of boating.
Where I launch you pay for the trailer as one parking spot and the car as another. of course you need to clamp it and ideally use a hitch lock as well.
Insurance is a must have considering the amount of thefts these days. a clamp and outboard must be left on otherwise a payout will be unlikely.
I don't know your budget but try and get a boat as complete as possible, the costs will soon rack up otherwise (atleast for me, i can't stop adding things
)
Agian i don't know your budget but don't under estimate other costs like lifejackets, clothes, fuel, training, maintanence. most can be kept relatively cheap though if you hunt around bit
Training wise you will need to do a VHF course. depending on what you are planning to do other courses like intermediate (day cruising) might be worth it. in theory you don't have to do any training or even get insurance but it's not really worth the risk.
Good luck
Nathan