Is your Origin up to date? I had a problem sending invites when it was not (as well as other problems). Otherwise, I think it's pretty straightforward.
Also, I apologize if one of those vets was me
It was up to date but I think I was just more used to Battlefield 4 which was a lot more convenient. Friends are shown right in the server browser, inviting them to a game is a snap, they get in when there's room in the server. Titanfall, things kept happening and we kept losing the party after a match, also it's awkward that someone kind of just picks a playlist without any real input from the rest of the "network." I also don't like alt-tabbing to invite people or to accept invites, but maybe there was some Origin overlay I'm unaware of.