Flexible shifts hiring in Portland

I am looking for part-time work that fits around school hours and found a few evening shifts near Portland. Any experience at all would help. Shifts are four to six hours and the pay is weekly. Is the schedule really fixed?

I worked evenings at a hotel. The hours were steady and the team was friendly, but weekends were busy.

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