Flexible shifts hiring in Fresno - any advice?

I am looking for part-time work that fits around school hours and found a few evening shifts near Fresno. It has been weighing on me all week. Some roles have a small tuition benefit. How many hours do they guarantee?

Keep everything in writing and save the confirmation numbers. It saved me later.

Ask whether the schedule is posted in advance and how they handle swaps. It matters a lot with kids.