Most sellers here have something else going on. Nothing requires full-time attention, and nothing penalises you for being unavailable — as long as the app knows.
That last clause is the whole of this page.
The three settings that do the work
1. Your dispatch time. Set it to what you can keep on a bad week, not your best one. A store promising 24 hours and taking three is worse than one promising three and taking three — the number is a promise. How to set your dispatch deadline
2. Your closed days. The days you never post, every week. Deadlines are built around them, so you are not late for being at work. Can I pause my listings for a holiday?
3. Daily capacity. How many orders a day you accept. Set it to what you can genuinely pack on an ordinary evening. It feels like turning away money; an order you cannot fulfil on time is worth less than no order. How to set daily capacity
Those three turn "I have a job" from a problem into a configuration.
Shows, if you want them
Pick a slot you can actually keep, and keep it. Once a fortnight kept beats weekly missed.
Evenings and weekends are fine — your own Timing tab tells you when your buyers are actually around, which may not be when you assumed. How to find your store's numbers
You do not need shows at all. Plenty of stores sell entirely through listings, which run while you are at work. Can I sell without going live?
What to batch
Photograph and list in one sitting, not item by item.
Pack in one sitting, with everything in reach.
Answer messages twice a day rather than whenever one arrives. A reply within a day is fine; being permanently available is not sustainable and nobody expects it.
What not to let slip
Dispatch deadlines, which are measured.
Returns and disputes. An unanswered return freezes that order's money and counts against you. This is the thing that quietly goes wrong for part-time sellers more than anything else. How returns work
Telling people when you are away. A message costs nothing; silence costs a review.
Going quiet for a while
Nothing is taken away — no inactivity charge, no deadline. Finish what is open before you go, and the store waits. What happens if I stop selling for a while?
More: what does a realistic first month look like, is selling live worth the effort, I got far more orders than expected.