Welcome aboard, Donzi !
There is no better source of information about motor assisted bicycles, on the planet, than here !
And a very helpful group of people !!!
I'd suggest you read a few threads that might catch your eye, and that will probably lead to searching through other topics.
The inexpensive MAB kits are the most fun you can spend your personal transport dollar on! They are very economical to operate, and are quite easy to work on with basic tools. The downside is that they WILL require attention! lol
That's part of the fun value, though.
Best to purchase a kit from one of the vendors who advertise here, as they do strive to deliver a better product, and are generally available when a discrepancy occurs.
Alf has put together a couple pages relating to preliminary inspection of a kit, before assembly of a MAB. It's real important.
My best tidbit of advice might be that riding a MAB is somewhat similar to riding a bicycle downhill... all the time!
Brakes are very important.
I do not feel coaster brakes are acceptable, and a MAB, for use in traffic, should have both front, and rear brakes.
Good luck
rc