and only the Get button available.
'Get' means you don't own the app yet and when you see 'Open' that means you own the app or have ever downloaded the app and then uninstalled it.
and my storage is only 60% full.
Try first to free up your iPhone device storage.
1.
Try to free up iPhone device storage see this Apple articles below:
If you need more space for an update on your iPhone, iPad, or iPod touch
If you need more space for an update on your iPhone, iPad, or iPod touch - Apple Support
How to check the storage on your iPhone, iPad and iPod touch
How to check the storage on your iPhone, iPad and iPod touch – Apple Support (UK)
Clear Other storage on your iPhone or iPad
Clear Other storage on your iPhone or iPad - Apple Support
2.
What's the difference between device storage and iCloud storage?
What's the difference between device storage and iCloud storage? - Apple Support
See this Apple article: Upgrade to iCloud+ -> Upgrade to iCloud+ - Apple Support
See also: iCloud+ plans and pricing -> iCloud+ plans and pricing - Apple Support
Manage your iCloud storage
Manage your iCloud storage - Apple Support
Then try again to download / install apps.