Project - HCP data - Possible analysis for finding correlation between brain regions

During brainstorming for our (@rutvipra7736, @pankaj)project on HCP dataset, we realized we have a valid scientific question but as all of us in my pod are new to analysis on time-series data, no one exactly has an idea how to go ahead with the core technical parts. We want to:
(a) divide our subjects based on age and then,
(b) find out if there’s any difference between their brain activities when both of them are made to do the same task

For this, all we could think of was to find out the correlation between different regions of brain (pearson correlation maybe). Now, due to time constraints, we thought that a network analysis would be too complex and will need close supervision from an expert which is highly unlikely as everyone’s schedule is jam-packed, so we were thinking of something basic like finding out correlations or something simpler than networks.

Kindly suggest any, like ANY feasible analysis that can be done on the mentioned idea (which is feasible to implement by a group which is new to time-series data, within 2 weeks of course). Any analysis, be it different types of correlations or some other method which can enable us to compare two groups’ brain activities during different tasks.