KODI NOT RESPONDING BLANK SCREEN LOST MAIN MENU

Hi I am new to Kodi and android boxes and I was wondering if someone could help me out please? I have the x96 android box and it was working rather well until I decided to try a free IPTV paid app. I had to install the IPTV Stalker Client PVR and a friend of mine came over and tried but it always said failed to load and alos got message no pvr addons could be found, you need a tuner, backend software and on the main screen no TV icon was there so he went into Skins and appearances and then in the start up menu he change it from home screen to TV and then when he went back to the home screen where I usually had the video, programs, system and it was all gone, totally blank, nothing on the screen. Can someone please tell me what happened and how to get back what I originally had on the screen as he told me that I could uninstall Kodi and reinstall it but he was not sure that I would get everything back ? We also tried a from the apps menu on Kodi a Force Stop and Clear Cache but it did not help as it was always saying computing ? Any help would be really appreciated as I have a paid app and I do not want to lose anything. Thank you