Cooperative missions

Hello, I really like this new skateboarding game. I had already played Skate 3 a lot, and so far this one is really fun. I just have a small issue with the tutorial mission that requires cooperation (the more the merrier) in french ( plus one est de fous) in step 4/5. The problem is that almost none of my friends on Steam play this game, and I've been trying for an hour and a half to join a group to complete these three cooperative missions, but for now I'm stuck at this stage of progress. I understand that my request may seem surprising, but is there any way to complete these missions without being in a group, or to join specific groups for this mission? 

That's all there is to my problem. I play on Steam on PC, and my EA ID is gregth57.

Thank you in advance for your help, and good luck for the future :) 

Kind regards,