I can’t download any app even everything is okay.

Hi crishaQUI,

welcome to the Apple (user-to-user) Community!

Re: "I can’t download any app"

Check you are signed in to your iPad with your correct Apple ID:

Sign in with your Apple ID - Apple Support

Check if your iPad needs updating to the newest compatible iPadOS version:

Eg: See if an update is waiting to be installed in Settings > General > Software Updates.

(If so, it is wise to back-up-your iPad before updating.)

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Else:

If you are signed in to your iPad OK, and using the newest compatible iPadOS version:

See: If you can't connect to the App Store, iTunes Store, or other Apple services - Apple Support

or

In the app store: Apps with a GET button are free, apps with a price are not.

See what to do: If you can’t download or update apps on your iPhone or iPad - Apple Support

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Re: "whenever I try to click an app with a cloud it downloads for a second and gets cancelled all the time"

An app with a cloud means you are trying to re-download an app you have downloaded before.

See: Redownload apps and games for your Apple devices from the App Store - Apple Support

Are you sure you do not already have the app in your app library ?

It may be already available on your iPad, even if it's icon is not on the home screen.

See how to search your app library: Find your apps in App Library on iPad - Apple Support

and

If you find the app in the App Library, and you want to add the app's icon back to the Home Screen:

See how to "Move an app from a folder to the Home Screen" in the article: Organize your apps in folders on iPad - Apple Support

Else: Trouble-shooting: See what to do: If there's an issue when you redownload apps, movies, or other content from Apple - Apple Support

All the best :-)