What to do when my phone storage is full

You have 2 choices:

1. Delete stuff you don't need or save stuff onto your computer before delete.
2. Buy an iPhone with bigger storage.

Note: iCloud Storage does not increase what you physically have on iPhone.

This article might help.

Manage your photo and video storage

https://support.apple.com/en-us/HT205703

You can upgrade your iCloud storage to store more files or data https://support.apple.com/en-us/HT201318