Android has this stupid thing where if you have about 1gb of space left, it won't allow you to install apps. Try clearing out some space.
Clear cache for some apps in the settings. Discord, Youtube, Google Playstore and Google Play Services are usually the biggest offenders, but basically whatever you use most will probably need it as well.
Move any images you have either to your SD Card or somewhere like Google Drive, One Drive, Imgur, etc.
Move the installation file to your SD card before running it.
Make sure you have Allow Apps from Third Parties enabled.