Basically we are thinking about cutting the cord at our house and just having internet. We have a grandma living with us, how difficult would it be for her to adjust to using this? I have never used it before either so I'm not sure how difficult it is to use. Also what would be the best boxes to get and is it best to order them off of amazon or other sites?
I have my 70 year old mother staying with me while she heals from an injury. Once I showed her how to use the Shield in my living room, she was off and running. The only thing that was somewhat difficult for her was the touch volume on the Shield remote, but everything else she is doing well with. As far as Android TV boxes go, the only new retail options out there are the Nvidia Shield ($200) and Xiaomi Mi Box ($70).
An Nvidia Shield TV with Netflix is just as easy to use as any cable box.
I would probably suggest a Roku for older folks. It has more content options right now and might be easier to use. We're never going to suggest those cheap import boxes running the Android smartphone/tablet OS. This subreddit is about official Android TV devices: Nvidia Shield, Mi Box, Nexus Player, etc.
Honestly, if you have good reception, I think she would be much happier/satisfied with "old fashioned" OTA TV. Get an OTA antenna for reliable, high quality HD video, for live events (SuperBowl/Olympics), news, or emergency weather/disaster situations. This is also a good way to offload your TV viewing from your broadband connection. DVRs are an option. Go to TV Fool and post a link to your report in /r/OTA for antenna suggestions. Be sure to mention if you want an indoor, outdoor, or attic antenna and if you want single or multi-room viewing or DVR suggestions. In many situations you can reuse the existing coax cables in your home.
I tried to convince my mom to go with an OTA antenna prior to switching from cable to DirecTV. It's probably been around 10 months and she's finally coming around that OTA TV and some streaming options would work better for her.
My ideal whole-home setup...
I would distribute an OTA antenna over all the TV coax (RG6) connections for grandma or in case you have a guest over and you just want to give them the remote and let them channel flip without having to explain anything. This would also be useful if your DVR is busy with no tuner available for watching a channel live or if the TV doesn't have a settop to access the networked DVR or internet.
I would then have a 4-tuner TabloTV connected to the antenna and networked via ethernet distributing video to tablets, settops, etc., ideally via ethernet (Cat6) when possible: use WiFi for portable devices, use ethernet for stationary devices.