I have deleted many items - documents, videos and applications from my Mac then I deleted other items from the I cloud drive and still it shows as no storage space available

Try going to iCloud.com/iCloud Drive using a computer browser and click on Recently Deleted at the bottom right. If there are files there you do not need, delete them. Then try iCloud.com/Settings using a computer browser and go to Advanced at the bottom left. Access Restore Files. If there are files there you do not need, delete them.

See this article https://support.apple.com/en-in/HT201318