Storage

Hi everyone, so I absolutely love taking photos and videos and hence why I saved up and got the 17 pro but why the hell is this thing always running out of storage. Can someone please advice me on how I can backup photos and not loose its original quality.
With icloud I have a backup already from when I had the iPhone X and apparently iCloud is a syncing application not backup?? So it will delete my previously backed photos and only back this one? Atleast that’s what I have heard. If someone can help me out I’d really appreciate it