G
GeniMan
Yes there is a Sith Empire (
Link), and yes you can make a Sith in the Sith Empire.
I would recommend going through the Timeline (
Link). That covers the grand scope of things. Chaos is set around the year 860 and slowly progresses in little leaps so time moves forward. All factions have a little bit of their own spin on things, and most have their own bits of writing to read about how they function, what lore they have internally, and how they work.
There is the factory and codex subforums for creating and codifying new species, planets, technology etc. If you find something on wookieepedia that isn't banned in the factory or on the restricted list, it's fair game. If it's restricted, there are some strings attached, as detailed in the factory and codex rules.
Beyond that, the world is your oyster. Just try to have fun, and do hit us up on Discord if you want.