||start getting familiar. Those are what I used (and still do, bookmarks on my browser) when I bought my TT back in the summer of '18:
I second the idea of getting into it gradually, otherwise, it can be overwhelming and you have a good chance being in a lot deeper than you intended. Typically, breather mods are the first phase, along with an ECU tune and boost jets/boost controller. At that point, you'll have a VERY nice, smooth-running TT and can make your next decisions from there (E85, bigger turbos, etc...).
Breather mods include, in my personal order of preference: cat-back, downpipes, testpipes/high-flow cats, dual intake, intercooler & piping. I still need to do the last two :)