C for character/sheet will list you skills and talents and reputation in towns and what not...

J for journal you should do this as soon as you create your character to get started in your quests, this will show your quests...

i for inventory this will show your inventory/backpack with different tabs for items... for example weapons/armor and resources...

R: If you find yourself walking slowly weirdly press R it's a Rp-walk toggle thingy... It makes u uber slow so just press R to go back to normal speed lol

T: For chat you can type your text and also enter console commands (see faq on discord for command details)

CTRL for sneaking you will see a blue meter-bar thingy if it's full of blue you're being noticed