Launching is a bit limited down our way. There is a good accessible slip in Dover harbour from which you can access the nrecreational part of the harbour which is good for getting familiar with the boat.
Also Dover Watersports based in the harbour do the RYA Powerboat course which is worth doing if you are new to the sport.
Otherwise there are a couple of slips on the N Kent coast as Whitstable/herne Bay
Apart from that, beach launching is limited unless you have a very light outfit as there are no slipways bel;ieve it or not
So options depend on what outfit you go for.