When looking to buy an audio Interface the first thing you need to know is how many input and outputs will you need, it's a good thing to think of the future also. Maybe now you will need only 2 but down the road you may need 8. What if any analog instruments will you be playing? Do you need it to have midi I/O? What is the I/O of your computer USB 2, 3, Firewire, Thunderbolt? Will a mixer style interface be better...ect
There are so many interfaces out there so the most important thing is to know what you need then what is your budget, then just buy it.