My main file, Dealers, has a portal that shows the related records from Contacts. I need to be able to export the information from Dealers with only the first Contact from the portal which will probably change each time we export.

My idea is to create fields in the Dealer file for first and last names, email, etc. then create an export script that when selected will take the information from the first row of the portal for contacts and insert it in to the fields in Dealers. That way we are just exporting 1 contact.

Is there a better way?

A calc that just amounts to

Dealer::Name

will automatically pull data from the first related record according to the relation's sort order (creation by default, but I assume you have it sorted differently). Likewise with your other fields.

Oops, I should clarify. I meant that you should include *on* the dealers table layout a field which is Contacts::Name, or define a calc field to be Contacts::Name.