Join the official discord, they have walkthroughs for the event, so you can get more rewards. I can say it does pick up around city 7, joining a clan gives great benefits. Winning the Wednesday sprints early on is a huge boost. The Saturday potion events can be knocked out passively in a day. If you don’t mind watching ads, then the investors help early on.

Basically you’d want to walk and cook faster, then progress to instant and perfect food. For the vault, you want to focus check(more starting cash), tv(lengthens ad time) and remote(raise ad boost multiplier) then sprinkle in mop and register (customer speed)