I have played online RPGs before, but nothing as complex as this one. I don't know where to start!
I created my character and created a story for her and given her some skills to match that story (some of the skills don't seem to do anything yet but ho hum). I read the newbie guide and found that it's better to join a faction before picking a start location. Does that mean I have to find a faction based on Muun (my homeworld)? Is there anywhere I can browse all the factions with a base on Muun to see if there is one suitable? If it helps I would like to do something non combat/action orientated, maybe mining or trading, maybe moving into R&D once it gets coded.
Probably read up the various guides, linked to at the top of the page, if you haven't already.
As for a faction, you don't have to have one based on Muun, you can join anyone you like. If you haven't spawned yet, you don't have to spawn on Muun if you join a faction - they should have at least one HQ that you can spawn at that will be close to their operations (or should be).
As for the factions, click the rules link at the top of the page, and on the sidebar should be a Factions link. The first one. Click that and it will list all the factions in the game, including the rough category they are in (mining, government, ship builder etc), so have a look through the factions that are doing what you want, and then have a look at their site to see if they appeal to you.