Welcome to Dakka, ninjadude.
In response to your question, I would begin simply with an
HQ and two troops.
Play several small games to get the feel of the rules.
When the starter box comes out, you can greatly increase your force.
Following this path will allow you to paint your army in small, manageable groups.
When the new codex comes out, you can pick a more specific theme for your force.
Hope this helps.