Change your dataset's name, its unique identifier and access its attribute table.
Access Parameters
Go to the Data tab of your portal, and click on your dataset's row:
A Information Panel will open:
Change your dataset's name and its unique identifier
Click on your dataset's name on the top of this panel to change it:
Make sure you save it using the validation button when you are done.
This tab will also allow you to change the unique identifier of your dataset. Click on "auto-generated" at the bottom of the tab. You will get a list of all this dataset's attributes, and you can choose the one you want to use as a unique identifier. Some attributes are grey and inactive: these attributes do not have unique values, and therefore cannot be used as unique identifiers.
Access your dataset's attribute tables
Go to the Links tab and click on Data: 
You will see the attribute table of your geographical dataset. Click on it to access its parameters. This will allow you to parameter any column of this dataset, such as changing their datatype or their name.