| I think you'll be just fine with a Rumble 15 for a small practice amp - I've got a Rumble 115 and it serves me pretty well for practicing. The Embassy looks like a great starter bass. The first thing you'll want to do is to track down an instructor. Not only will you want to learn how to play your Epi, but you'll want to learn music so you don't have to use tabs. When you meet with an instructor, let him/her know that reading music is one of your first priorities, so that you get started on that as quickly as possible. Also, look for music with good bass lines and try to pick them out by ear - after you've done it for a while, it gets easier. It gets much easier the more music theory you learn.
There aren't any tricks to playing bass - like anything worth doing, it takes effort, practice, and grit. Good luck! | 
