depends on, but typical assignments for MI officers after they get comissioned are assistant S2s, platoon leaders, and "staff" officer.
Assistant S2 - mostly office work, intel analysis, generate intel product
Platoon Leader - leading your platoon (12 to 30 soldiers)
"Staff" officer - mostly office work
Once you become CPT and above, there are more opportunties to work at Echelon Above Corps (or what I call Echelon Above Reality) level, such as NSA, DIA, and other national level intel agencies.