If this was a pre loaded stick, I would recommend you remove Kodi completely and start fresh. You likely have tons of crap you have never used and don't need. A fresh start will give you what you need.
Download Kodi for Android from kodi.tv/downloads
You will also need ADBFire to sideload it to your stick from your computer. I believe there are other apps to help with the sideload thing. Once installed, follow the tutorials in the Blog (top of the forum) for fusion and addon installer.