"The first card you foretell" refers to the first one you exile from your hand as part of the foretell special action. It doesn't refer to a foretold spell you cast from exile.

Ranar's triggered ability triggers only once for each time you exile cards from your hand or permanents from the battlefield, no matter how many objects were exiled at the same time.

Ranar's triggered ability will trigger when a spell or ability you control exiles any permanent, including token permanents and permanents you don't control.

Ranar has recieved an update to its Oracle text. Specifically, its triggered ability doesn't care which player is exiling cards and permanents. Cards put into exile from your hand for any reason, such as the foretell ability, cause the ability to trigger, and permanents exiled from the battlefield cause it to trigger if you controlled the spell or ability that exiled them.