Depending on your body type and generally how much mass you'd like to add, you may or may NOT choose to eat clean. But eating entirely clean 100% of the time is NOT necessary on a bulk. I'm not saying you shouldnt, but you do not need to.
Anyway without knowing these specifics, the easiest advice is to just eat more calories than you burn.
"Abs on a skinny guy are like big boobs on a fat chick - they don't count." -Shelby Starnes