TI4 is a 3+ player game, therefore if you only have two people you are pretty scuppered and your options are: don’t play; use one of the internet’s homebrews…
All in all, TI4 is a great game (though not the cheapest), balanced, not overly complex, quicker than you might think and with so much replayability. If you are the long hall war gaming type then you'll need to go into it understanding that it isn’t really a wargame, despite its look, it’s a game of diplomacy and threat… with the ability to war it out, if you must.
Nothing is better than a good paper and pen RPG, and by paper and pen I mean Roll 20 on your PC (seriously check it out!)