DO you get the control panel for icloud on ipad mine seems to be in a list rather than as a panel does this matter?
You cannot log into iCloud from your browser. iCloud services are connected to various apps on your device. Check in Settings > iCloud to be sure you are logged in and selected the appropriate services to use.
You cannot log into icloud.com form an iPad.
All icloud management and content access is done through the Apps that use iCloud.
You can set it up, through Settings->iCloud
And access content form it though the Apps such as Notes, Calendar, Pages, Numbers etc...
What exactly are you attempting to do?
Retrieving data ...