Knightley wrote:Welcome to Dakka,
You would get a better response if you posted this in the army lists sub-forum
This. This answers both questions you posted. You would have better luck in the
40K specific forums for questions about armies. As to what specifically to buy for any army starter, it really depends what you want to do. If you want the power lists type then troll around the forums for a while tracking down exactly the list you think would be fun for you to play that best suits how you want to play.
In the end, it really comes down to what will make it the most fun for you whether that is a
TAC list, power list, or fluff-type list.
Hope that helps!