I need to get either the total of repeating fields in a portal to display locally, or get a summary field from that portal query to display? Can anyone help me with some ideas?

Well I'm not completely sure what your situation is, but given a portal with a number field in it, you can sum that number fields by creating a new calc field like this:

Sum ( PortalRelationship::NumberField )

Aside from that, I'd just search FileMaker's built in help for "sum" and then read the first entry ("Sum function"). This discusses the case above as well as its application to repeating fields.

Best,

John