Hi my phone keeps telling that it doesn't have storage to use even though I just bought more storage on my icloud

Purchasing the iCloud storage option.. this does not expand the storage capacity of your device. You cannot expand the storage capacity of your phone. Unless you're using iCloud Drive to store files, iCloud is more of a 'syncing' service.

Here is how to check what is taking up all your space on your phone

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

If the majority of you space is being taken up by photos, and you are using iCloud Photos.. make sure you have the Optimize Storage option turned on.

Set up and use iCloud Photos - Apple Support

Otherwise if you are not using iCloud Photos, you can transfer the photos to your computer and remove them from your phone.

Transfer photos and videos from your iPhone, iPad, or iPod touch - Apple Support

You can check how much iCloud storage space you are using here:

Manage your iCloud storage - Apple Support

Note that when you delete photos/videos they go to a 'Recently Deleted' album where they may be classified as 'other'. To completely remove your photos from your device you would need to empty out this album.

You an also check the Files app and see if there is anything in the Recently Deleted area.