How can I clear incorrect iPhone storage space to update software?

My phone keep malfunctioning telling me I don’t have enough storage to update software. When I go to storage settings on my phone it suggests to add more storage space. However it’s reading my photos and videos as 2000 plus when that’s inaccurate information and it’s counting large attachments that I previously deleted. The system space on my phone takes up more than any apps or photos I have on my phone in which I can not delete the system data in my settings. How do I clear the in correct settings of my storage space?