Macroeconomics v Microeconomics
[...] are there any ways in which Macroeconomics help us to understand the behavior of individual units?


Putting aside the totological cases in which a utility would directly integrate macroeconomic signals such as, e.g. key-rates, AFAIK, no there are not. 

As you mention, Macroeconomics is about aggregate level considerations and/or identities That being said, you will find theoretical frameworks, such as  General Equilibrium Theory that imply/represent microfounded behaviours with the intention of adding them up instead of directly dealing with accounting-like macro aggregates.