About iPhone 6s Plus
Please how can I have space on my phone when there is no app video or photo on the phone
iPhone 6s Plus, iOS 13
Question marked as
If you are running short of storage look In Settings, General, iPhone storage .
Display all the recommendations and study them including emptying Recently Deleted album.
Consider importing photos to computer and syncing back (they're half size when sync'd)
If you have unlimited wifi and want to buy some monthly icloud storage consider iCloud Photos.
If your “Other” storage is more than say 6GB then
How to back up your iPhone, iPad, and iPod touch - Apple Support
Restore your iPhone, iPad, or iPod to factory settings - Apple Support
Restore your iPhone, iPad, or iPod touch from a backup - Apple Support