what my storage is full please helpp I want plus my gb

If your asking to add storage space to your phone, you can't. It is a fixed size.

Here are a couple of articles to help you free up storage on your phone.

How to manage photo & video storage.

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

How to clear "other" storage on your phone.

https://support.apple.com/en-us/HT211686

Are you seeing a message that the iPhone storage is full or something else? If the iPhone storage is full, the only way to get more room is to delete some content on the phone. You cannot increase the maximum iPhone storage that you purchased the phone with. See this, How to check the storage on your iPhone, iPad, and iPod touch - Apple Support