I tried out both GBO2 and Border Break around the same time when I got around to making a JP PSN account, and Border Break is by far the better of the two. The top menu option is to play, and the first is below-rank 10 matches, second regular matches, and the final for bot matches. Second menu option is a tutorial, which I recommend anyone try before playing online. This'll get you in and playing until someone gets around to translating the lot.
The game itself is great, probably the best modern multiplayer mecha game. It's not obscenely p2w, mostly just sidegrades. The starting sniper rifle sucks, and the current meta is to unlock the second mortar type which you get from reaching a certain rank, and then spamming the shit out of it on contested points. If you see or hear artillery falling, run like fuck, you will die. Other than that you shouldn't have any disadvantage for not spending money, and you get a certain amount of free cash just for ranking up. There will always be at least one player in any match who will instantly mop the floor with you on sight, and has probably taped their hand to the controller. If you want to be sure you're useful, play support and drop your mines and radar deployables around contested areas. Even if you die, it's still helpful.