Four years to the day, I published what went on to be one of my more-visited articles, a brief look at installing LineageOS on a Google Nexus 7 (2013 Wi-Fi) tablet. Alas, the LineageOS project no longer supports the Nexus 7 and after getting a good 20ish months of use from my LOS Nexus 7, it became unbearably slow and lost its usefulness in any event.
https://thenewleafjournal.com/installing-lineageos-on-a-2013-nexus-7-wi-fi/