I've used and owned loads of Seagulls over the past 50yrs and I would say they are not the best outboard for a novice beach launching unless it is dead calm and you know it will be dead calm when you return. They are very low powered and you will not have the ability to position yourself against any waves rolling into the beach and a launch against any sort of waves can be quite difficult.
As apshutt advises I would try river, canal, lake or perhaps a quiet harbour/safe estuary situation until you are happy the engine is OK to operate and appears reliable.... and to give you some feel for the boat before facing the open sea.
I don't know the area but what about the river Stour near Sandwich (it appears the lower reaches near the sea dry at low water and may be tricky). There is a slipway by the pay and display car park to the south of the river in Sandwich. Here if this works...
Seems you can launch and have 2hrs either side of high water from the slip and there is loads of room in the car park by the slip to get set up.
Others who know it well may advise.