I need more storage and I don’t know how to do it

You are not going to expand the storage space on your iPhone. Your iPhone's storage capacity will never change.

Are you referring to more storage space on iCloud so that you can sync and backup your data to it? If YES, then review these guides published by Apple 👉 How to upgrade to iCloud+ and also review this guide 👉 What's the difference between device storage and iCloud storage?

Axel F.

An iPhone's storage is a fixed size and can't be increased.

If you mean you need more iCloud storage, look here -

Upgrade your iCloud storage plan -

Upgrade to iCloud+ - Apple Support

Click on the blue text in my post.