Hey, no worries! Like seriously, I am here to help. I can't really tell you how to start RPing, as different people feel more comfortable in different situations. Most RPs here are text based, but whether or not they are text heavy really depends on the people in the RP. You could check the currently running RPs, or check out what has been posted in the SU section (I would definitely recommend going for a plot you like over a plot you don't care for). I have one that hasn't started that currently just has LKwayvern and I, but I know I tend towards being really wordy (not that I expect anyone else to be). If you have an idea and want to try making your own RP, that's also an option. It really depends on what you're interested in/prefer. We also have the forum RPGs, which I believe are less text-heavy, but I don't participate in any of those, so I'm not quite sure how those work, or if that's the kind of thing you're going for, though I could see if I can hunt someone down for you.
Hi there, Shenili! I'm actually not WinterVines (They go by the same username here, though I don't know if they are active anymore. If you happen to be from PE2K, I went by Winter-Cherry and Riika-chan.). As far as I know, there isn't one. I haven't really seen SUDT used, but I would assume where SUDS usually stands for "Sign Up and Discussion," the T is "Topic."