Hi

Firstly welcome to the forum, you’ll get plenty of help and suggestions here.
You are going to have a lot of fun with the Falcon kit, it is a superb build. The tools you need are basically super glue, tweezers, modelling knife and a couple of decent screw drivers, although you do get one with the kit. As for characters, these are not included but you can buy third party parts from such places as Shapeways, although these can get expensive.
There are also plenty of members build logs here to give you ideas, along with my custom build too. This is such a versatile kit, you can just build it straight from the pack or add your own interpretation to it.
Whatever you do though, I look forward to seeing your progress.

Regards
Mark