So as an absolute beginner..

As an absolute beginner who has never played any of the games from the drop down list, what exactly do I need to do to play D&D for example, like character sheets and stuff, or is there like tutorial/guide which would point me in the right direction?

Welcome to Roll20 Ryan! Happy adventuring and gaming. Roll20 has some videos that are at your disposal for help getting started. 1) If you're absolutely brand new to RPGs and want to know the general idea of how they are played, which game to choose and then find a group of fellow gamers: Check out our Introduction to Tabletop RPGs series . 2) If you've played tabletop RPGs before and just want to get a understanding of how Roll20 can be used: Check out our Roll20 Crash Course . This is a step-by-step overview for creating your very first Roll20 campaign. This tutorial uses the Pathfinder RPG to frame itself, but it's not a system specific tutorial and you should be able to follow along without knowing one single thing about Pathfinder. Hopefully this will make acclimating to RPGs and Roll20 a lot easier. 

Also, if you hover over the word Games in the banner up top, you will see a Tutorial which will help you learn the Roll20 virtual tabletop interface.