Keeps saying my storage is full even when I delete a lot of stuff

Did you restart the phone after each deletion? The only way to get more storage space is to delete photos, messages, apps, etc.. Be sure to save important photos and data to your computer or an external drive. Check these links...

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

Clear Other storage on your iPhone or iPad - Apple Support

Here is a video which may help...