Keeping tabs on teams, units and gear. help

Hello there, i have been sitting on something for a few days, and i cant for the life of me work out how to even start to go about it… with this in mind i really dont know if im going to be asking the correct question, but here goes.

im currently working on a top down TBS game, that will have different classes and units, also different active teams in different areas, think of it like the Xcom: Enemy Unknown teams of up to 6, but multi teams sent out at once and different things happening to them etc etc

would i be right in thinking to make a system like this, i would need a data file composed with all the teams, and units etc? because thats one of the issues im having, is working out how i can keep tabs on different units, in different teams with different gear. half the information i have looked at says it should be data files, and the other says blueprints to make it dynamic, if a unit in team 3 was killed for example…

can anyone please help with even where to start here? also im kinda new to blueprints but have been learning as i go so i get most of the terms used even if i go cross eyed

thank you in advance