Im new to the site how do you upload comics?

Welcome! First you have to make an account for that comic. At the top of every page, there's a link in that green bar which says "create" - click on that and you'll be taken to a page where you fill in the information, like the comic's name and a description and stuff! Once that's made, you'll be able to add pages to it.
 
To add pages, look to the right side of the screen, in the yellow side-box which says "Hi, Yuki Smith!" Click where it says "my comics" and it will expand out your list of comics. Click on "edit" next to the comic you want to add pages to. You'll be taken to your comic's control panel. From there you'll see some buttons/options to let you change basic things like the description, as well as add your pages! From there it should be pretty straightforward.