I need more storage for my iPhone

Welcome to the Apple Support Communities.

See: How to check the storage on your iPhone, iPad, and iPod touch - Apple Support.

If you are referring to iCloud, see: Upgrade to iCloud+ - Apple Support.

Jack

There are third party USB sticks with apps to backup your photo gallery/ videos / contacts.

This should put you back with more space.

And you forgot to mention how much space your phone has

settings > general > iPhone storage

Your phone will never have more storage than it did when you bought it. You can try to free up storage by deleting stuff, but if that doesn’t work you will have to buy a phone with more storage.