Launching and retrieving a small boat alone really isnt much of an issue.
But you will get your feet wet, so wear the proper type shoes.
All you need is about 30’ of about 5/16 rope attached to the bow with a loop on the opposite end for putting over the winch post.
Where i primarily fish there is no dock and a very poor ramp, but if an 87 year old man can still do it, so can you.
I would much rather get a little wet pulling it back onto the trailer with the rope than i would climbing down off the boat after its loaded.
As for wiring the vehicle, get somebody who knows how to do it for you.