I am new and you probably are tired of answering n00b questions but I would really like to know so I don't spend the few resources I have on something that wont help me expand.

Also there is a guy that has been away for a month in my (area?) how do I take over his planet? (It has a moon is why I want it)

Well colony ships "colonize" uninhabited planets and you cant steal others planets.

Moved and locked

Just one topic will get you the answer you need