The Insignia 50-inch Smart 4K UHD - Fire TV Edition may sometimes freeze up and get stuck on the home screen due to either a lack of memory, or due to changes to your WiFi / router. The remote could also need to be paired (or faulty). But often with computers, if you just unplug everything, turn it off / on and restart, it will resolve the problem.
So the TV starts freezing up, I recommend you unplug your Router and WiFi network, then also unplug the Insignia TV to reboot it (don't just turn it off with remote). Then go into Settings -> Apps, and delete any un-needed data from Apps that you do not need to free up some internal memory. The TV is cheap for a reason, and they seemed to have skimped on memory and power.