iPhone storage

Hello,

I am asking today about my iphone storage. I am currently using 63 of my 64 gbs and I do have a lot of photos that I want to save. My phone has been not working well ever since. I have icloud set up, but it hasn't helped too much so I was just wondering the best way to optimize and save my storage. Should I store all my photos and stuff in a storage unit device or is there something better?

Thank you