I need to choose a tablet or something. I realize I know very little. We want to read books, but I realize there are tablets out there that will do more than the Kindles and Nooks do. I suspect the prices are similar. What is a Nexus? I really do not know what I need, but I do need help.
First of all Charlotte, Nexus is a kind of Android tablet. It’s the name used for tablets manufactured by Google, the owners of the popular Android tablet operating system. Android is an operating system for tablets and smartphones, much in the same way Windows and iOS are operating systems for computers.
Kindles and Nooks are also Android tablets, but with specialized versions of the Android system that have been altered to put the emphasis on certain products and services. Kindles emphasize Amazon, while Nooks emphasize books and other services from Barnes and Noble.
Really other tablets don’t do much more than an Android or a Nook. They are all Android tablets. But when you have Kindle, you are limited to downloading apps from the Amazon App Store and reading eBooks that are compatible with the Kindle. But you can also access Amazon Prime Video and the Kindle Owners Lending library if you pay for an Amazon prime subscription.
On other Android tablets you can download both the Kindle and Nook apps and have access to books purchased at either site. With the Kindle, Nook and other Android tablets, you can also download apps like Overdrive,  that will allow you access books from libraries.
You will see a lot of options for Android tablets out there in a variety of price ranges. Sometimes an unbranded tablet is your best bet for value, coming in at a substantially lower price. All tablets should allow you to access e-mail, surf the Internet, read eBooks, watch videos and play games.
You will need to have a WifFi connection available. You can read eBooks offline, but for updates, purchasing apps, e-mail etc… you need to connect to the Internet.
I’ve just discussed some of the Android options. You could also consider an iPad or a Windows tablet. 
Now, if reading books is your only interest in a tablet. You might be perfectly fine with an eReader,  like the basic Kindle or Nook.
Hope this information helps with your decision.