You can get a list of campaigns avaialble in your account by using the GET method on the campaigns collection:
The GET on the campaigns collection returns a list of campaigns as described in the Campaigns Collection Reference.
Each campaign is returned in <entry> tags, and if there are multiple campaigns, there will be multiple <entry> elements. Each entry provides only the basic information about a campaign, such as the name or title of the campaign, its author and status. To get more details for a particular campaign, you need to use the <link> provided inside <entry> to construct a new URI and query the campaign itself, and the resulting URI would look like the following:
If you call the above URI with GET, you should be able to get more details about the campaign. This action is described in more detail in Obtaining a Campaigns Information section.