Aside from enabling ADB mode in developer options you can’t really do anything to that firmware at this time. You can’t unlock the bootloader to install a custom ROM and no ROOT at this time. You can however install the google play store, just google “google play store on fire xda” and there’s a straight forward tutorial on how to install it. From there you can install a launcher to give it an Android look. When not using the table enable airplane mode to avoid auto OTA updates.