The "Together is Better" and "People Person" Achievements can both be easily earned
Simply:
-Have a second controller connected to another account(not guest)
-Create a club(will give you "Join the Club!" Achievement if you have not gotten it yet)
-Invite second account to club by going to bottom of screen and hovering over their profile picture(after inviting them to a party)
-Once second account is in club, go to Play - Manage Club - Create Private Match
-Before beginning match, go to mutator settings and set max goals to 1 goal
-Then play 10 matches and both achievements should be yours