The game creates opponents based on your arena points, which is your rank on the server. It's not meant to be fair, it's a ladder, you have to get stronger and beat stronger opponents to push ahead. Every win adds more points which pushes you up the ladder and makes the opponents stronger, 90% of the time all of the opponents it generates for me are too risky to try and beat and I have to fight the bottom option which adds no points but still provides the usual rank rewards. When I jump up in power a bit then I can usually get a match I can win and I gain a few more points and climb the ladder a bit, then it's back to farming the bottom option. As a brand new player you are just at the bottom of the ladder and you need to gain enough power to start climbing, there's also probably a lot of variation down there as not everyone jumps into the arena right away.