Unable to update my Raspberry Pi

So I know that by nature, Kodi checks for updates when the Pi boots up. But the problem is it isn’t and I know this because when I go to try to update the twitch app, it says my OS is out of date when I go to manually update, the Pi freezes reboots and never tells me if it’s up to date. Do I need to reformat the SD card and start from scratch or what? This has been an issue for awhile and I don’t know what it’s not updating itself.