You'll be fine starting off with Intrigue, if you like it and have played through all the cards a good bit pick up the base game or the prosperity and seaside expansions.
There are two player variants out there for Catan but with no trading it's not as fun.
I think Agricola is actually a mich better game than Catan with more strategy and less luck. And you can play two player.
If you get Catan I think the Seafarers expansion is a must.
This post was edited on 12/7 at 11:48 am