Hello SaraLou2108,
Welcome to Apple Support Communities.
We understand that you want to check your iCloud storage but unable to do so because you’re in a loop to login. We are happy to help.
Do you have VPN or security software enabled on your computer and/or iPad? If so, we recommend disabling that and restarting both devices. Many times restarting can resolve many issues. Please use the steps here to restart your iPad: Restart your iPad - Apple Support
"How to restart an iPad without a Home button
- Press and hold either volume button and the top button until the power off slider appears.
- Drag the slider, then wait 30 seconds for your device to turn off. If your device is frozen or unresponsive, force restart your device.
- To turn your device back on, press and hold the top button until you see the Apple logo."
After your iPad has fully restarted, please go to Settings > Your Name > iCloud.
Let us know if you have further questions.
Take care.