I can't help you much as I'm fairly new to the game too... However you mentioned the lack of players to clear maps with and I've witnessed the same thing. I'm totally in for some runs so hit me up in game! especially given I'm at the same level range as you!

My ign:
-Rogue --> Outling L44
-Sorcerer --> Leapquest L41
-Warrior --> Gregogre L36

Otherwise my knowledge is very limited about ways to earn gold but from what I've understood, AL is much more centred around farming than PL (I'm also a former PL player).
The idea is to get a leprechaun pendant (15% reroll chance, costs 180k in cs) and luck elixirs (30% increased luck) if you have the budget (12k per elixir, or 4 platinum), and farm away for crates and eggs.
Otherwise you can always try to merch your way through, but I'm a bit clueless in that sector... I have no idea what the prices are and am overwhelmed by the diversity of items!
Also keep in mind gold is much harder to obtain in this game than in PL... MUCH harder... good luck!