A good start might be going through the tutorials in the Getting Started guide that comes with the software. If you are totally new, the will familiarize you with the software and tinkering around with audio and effects.
Getting "studio quality" takes practice, patience, and good ears. We could all list stuff here all day about compress this, eq that, etc., but you'll have to experiment (that and it's been done before here). Searching around the forum will provide you with a wealth of tips on mixing, what effects work best for what and more. There are some good people in here that do know what they're talking about - I've learned alot just by searching and reading! Cubase is a great program with great capabilities....it's just a tool though.
Good Luck.