Considering this is your first foray, I think you're off to a good start. As you're learning, mixing is not so easy as it seems :) I agree with the substance of the prior comments to an extent. It starts with the recorded sound, and then becomes a game of balancing elements. One of the hard parts is learning what those elements are, how they interact - as well as learning the tools you have to modify behaviors according to your intent. To be a performer and engineer takes a huge amount of knowledge and experience.
EZ Drummer will get you some of the way towards a drum sound but is probably better viewed as a songwriting aid rather than a source of killer sounds. I use SD3 and - being a retired drummer with 15 years touring under my belt - SD3 can be utterly convincing when programmed correctly. I do take the time to customize a kit and use the program's editing facilities to edit midi parameters, etc. I remove ALL Toontrack processing because it's overblown and I have better sounding tools in my DAW. So learning your options and selecting based on need is another part of the skillset. I'm a shameless acolyte of UAD plugins, but that's above your pay grade for now.
Many people here, me included, recommend Mike Senior's "Mixing Secrets for the Small Studio" as an excellent primer and reference book which you can find easily enough. Mike Senior is a contributing writer for SOS and really goes to serious lengths to help us mere mortals in our quest for a better understanding. Thanks Mike! *edit* There are a great many excellent helpful people associated with this endeavor who contribute copiously and generously. An oasis on the web. Thanks e'rybody *end*
I often go back and forth with mixing and writing AND honing my performances in an iterative process so that it's very hard to say "I wrote this, I performed this, I edited this, I mixed this..." in a linear way. Generally though, once I get to a level of clarity I'm comfortable with, then I'll go back and actually lay down tracks with focused intent and try to knock the fu**er out of the park. Hired (bribed/cajoled/begged for) help in front of or behind the desk is always welcome and generally ups the fun level significantly.
There are a million ways to do this and the absolute best way to learn some of them is to do exactly what you're doing. If you want to record, find people to record, find people who already record and ask for help. Be comfortable being vulnerable - and be at peace discarding or ignoring negativity. Stay focused on what's important to you and have fun!
The great thing about making mistakes is you get to learn from them!
Take my advice, I'm not using it.