iPhone storage issue preventing app downloads

It is not possible to buy more storage for an iPhone; it will never have more than it did when you bought it. What you bought is iCloud+ storage that is used for backing up and also for syncing to other devices. Here is an explanation→What's the difference between device storage and iCloud storage? - Apple Support

Go to Settings/General/iPhone storage to review what is using your storage.

iCloud+ has 2 independent functions. iCloud backups, and iCloud sync. It’s confusing because they both have the same name prefix. But they have no connection with each other. Go to Settings/[your name]/iCloud. You will see a bunch of switches (with iOS 16 or later also tap Show All). When you turn on a switch that data type will sync to iCloud. If you do this on multiple devices that share an Apple ID the selected data will sync to all of those devices. 

You can also turn on iCloud Backups. This will back up your phone every night if the phone is plugged in, connected to Wi-Fi and locked.

But note that these are independent functions; anything that you sync by the first method will be excluded from the iCloud backups.

You get other benefits with iCloud+

• Hide my Email, which lets you access websites without giving away your primary email account (and also track who they sell your identity to)
• Private Relay, which is sort of a super VPN (at much lower cost than commercial VPN)
• Custom email domain, so you can create a personalized email address that forwards to your Apple ID email (such as jane@doe.com)

montreaallen wrote:

why cant i download apps and it says i have full storage but i dont have anything , i have 3 photos , 2 apps and i bought more storage but it still doesn’t let me download things.

As the others have pointed out, what you bought is iCloud storage – not device storage. You can't download apps to iCloud – they must be stored on your phone, for the phone to be able to run them.

According to MacTracker, the iPhone 7 came with 32 GB, 128 GB, or 256 GB of storage.

iOS 15 itself might take something like 1/3 to 1/2 of the storage on a 32 GB iPhone 7, and game apps frequently want several GB each for the game and its associated data. If you have a 32 GB iPhone 7, you probably would have just enough device storage to "turn around in a closet" (metaphorically speaking), and you might run out of storage after downloading just a few large game apps.

If you bought more storage, that is for iCloud. However, if you can't download apps that is due to the physical storage on your phone, not the storage in the cloud.