Connor
So, talking about the naming and the bill and Ted's connection... Connor might be from the terminator flicks.
That being said...
I think when Connor mentioned it can't him who goes back... It's because he's, somehow, originally from that timeline. Way back.
They mention Connor can't go back (in a conversation with Rufus). They mention twice why the team can't go back immediately prior to the theft (they can't go back to where they already exist). Thusly, Connor already exists in that timeline.
That seems easy - practically spoonfed to the audience.
That leaves the obvious mystery, the obvious Mcguffin: who is Goran's character's relative in all this.