Want to view what's in my iCloud

You can view everything in iCloud by logging in to iCloud.com. You can also turn off iCloud entirely or deselect certain features. This Support Topic shows you how:

Change your iCloud feature settings - Apple Support

You can delete the files, but if you are syncing with iCloud, if you delete a file from iCloud, it will delete from your device/computer.

You can also see what is in iCloud by going to the applicable app. For example, to see your photos, go to the Photos app.