Is there any way I can create multiple relationship objects via upload? Is there any template for this? Thank you

You can create this custom NPSP object by upload. It requires two preexisting contacts which can make it challenging.

I use Apsona because I don’t need ids to match contacts.

I don’t believe NPSP data importer does support relationships easily or at least out of the box. I could be wrong if you approach it with custom mappings.

--Terry