The short answer is that you can't install to or move apps to the external memory in current generations of Android except for 5,x. Only media or the data from the few apps that allow you to specify where it can be stored.
Hi mcta1, congratulations on your Nextbook 7 and welcome to the forum. Glad you decided to join us here at Android Tablets.
Internal Memory AKA Internal SD Card (16GB in your case) is where apps are downloaded and installed to. The more you have, the more apps you can install on your system.
An external Micro SD Card (MSD) AKA TF Card (32GB in your case) is and always was intended as space to store your media files. Books, pictures, videos, movies, music files etc. are what you should be putting there.