You asked a literal book full of questions, brother.
The best way to start is to pick up a book. Square Foot Gardening is probably the best ever written, and I've read hundreds, literally.
It'll give you an excellent base of knowledge, it's simple, and it's a really fun read. Then you can start questions from there.
Seed starting is a whole noter game. It's very difficult for most. If you do it right, it's simple. And tons of fun. Come on over to my hoes and I can teach you in an afternoon.
