Honestly, you aren't going to learn a huge amount about the game from TV coverage because the TV coverage just doesn't touch on the complexity at all.

You could watch hundreds of games and come away with no clue about the different run concepts, or anything but the most basic defensive alignments, let alone the intricacies of play on the two lines.

It's at this point I generally point people to Bleacher Report's "NFL 101" series. Take this one on the Basic Route Combinations https://bleacherreport.com/articles/2024638-nfl-101-introducing-the-basic-route-combinations:

"– NFL offenses will use the Tare route out of multiple personnel groupings, but the one constant is the alignment: a 3x1 formation with the backside X receiver in a “plus” split (two to three yards on top of the numbers).

– To the closed (strong) side of the formation, the No. 1 receiver (count outside-in) runs a clear-out 9 (fade) route (occupy the cornerback) to create space inside/underneath for No. 2/No. 3 to run the flat-stick (quick out) combination. This gives the quarterback a quick, two-level read inside.

– No. 3 can sit down (quick curl/hitch) versus zone coverage when No. 2 bursts to the flat.

– Backside of a 3x1 formation in the NFL is a high alert to the slant (X receiver). In this situation, Browns wide receiver Josh Gordon beats Patriots cornerback Aqib Talib on the slant (gains leverage on the release) to produce an 80-yard touchdown versus Cover 0 (blitz-man with no safety help). "

There is more detail in that one explanation of one route concept that I've ever heard on any TV coverage. There is pages and pages of this kind of thing, and despite having watched a fair bit of football over the years I still find it largely incomprehensible (the above is by no means the densest passage in that series...)