Why I can’t download some apps like google?drive

As the others suggested, you need to update your iPhone before you can download the Google app. To update, select Settings > General > Software Update. If your device is eligible to update, you will be prompted to do so. You can find more information here:

Update your iPhone or iPad - Apple Support

I strongly suggest you set up automatic updates to avoid this problem in the future. Here are the instructions:

Turn on automatic updates

1. Go to Settings > General > Software Update.
2. Tap Automatic Updates, then turn on Download iOS Updates.
3. Turn on Install iOS Updates. Your device automatically updates to the latest version of iOS or iPadOS. Some updates might need to be installed manually.

Check the comparability section (App store > Search Google Drive > tap on that > scroll down to see comparability section ) of the application in app store where the application developers mention the IOS versions. If it says requires IOS 15.0 or later which means your device should have that IOS to install the app. You won’t be able to download if your IOS version is before the specified one.

Google Drive requests iOS 15 or later on your iPhone but, from your products list, it seems that your 8 is still running the prehistoric iOS 13. Should be this case, update it.

Regards

Giulio