Satriani is great, and a good guy. I got to work on the G3 tour for a while.
Welcome to the world of recording. There is a lot to figure out , but it is fun. My advice is going to be to keep things a simple as possible.
What you are looking for at this point is a DAW (Digital Audio Workstation) set up, which is essentially recording software. When people ask what software they should get I always tell them to get whatever most of their friends are using, because that will get you the most free tech support. That said, since you already have a presonus interface, you might want to take a look at the presonus recording software called "studio one". Lots of my talented friends like using it and the entry level version is about $70. Studio One will probably have most of the plugins you need to get up and running making music. If you want expanded options for a drum program EZdrummer sounds great and is fairly easy to use. Also, add a Shure SM57 to your mic set up. Every studio needs an SM57
Most important is to get a few tools and start making music and mastering those few tools. If you buy lots of new software at the beginning it will get overwhelming. I have been doing digital audio for decades and I even get overwhelmed if I get excited and buy too many new plugins on black friday.