Yeah, it's super frustrating trying to complete the co-op tasks. I joined open parties, laid down party beacons. It took forever to finally find someone with an open party doing challenges. My speculation is they try to push social engagement to try to get you to have FOMO when seeing other people's cosmetics....
I completed all the challenges except for the co-op stuff and still unlocked everything. Its optional
If you didn't do co-op, you didn't unlock the Month 1 task because you need to complete 50 goals in a party.
