Learn the full loop
After choosing a companion, get used to movement and the map. You do not need to keep clicking to attack. The mouse controls the camera; whether facing matters depends on the move.
In Classic, defeat each region’s Guardian and take its portal, then fight the map’s Legendary in the Sanctuary. The first Guardian is not the end of the run.
A lost run can still help
Runs award Stardust for permanent progression such as Lab upgrades. Early on, complete quests and learn map interactions before making victory your only goal.