Keep in mind hours are being cut at every store and there may not be opportunity to pick up hours at other stores right now

With the hour cuts it will be hard but definitely get your name out there, you are always welcome to call their store but if you have the time I would go inside, I feel like it leaves a stronger impression of "I will pick up shifts". If you do go inside I would bring a sticky note or something similar with your name and phone number already on it so you can just be like "Hey I am a partner from \_\_\_\_\_\_\_\_\_\_\_ store and I am looking for more hours so if you ever need someone feel free to give me a call!" Then they have it written down and will hopefully put it somewhere that other shifts/SM can see it for when they need coverage. I've covered at 2 other stores in my town and honestly I enjoy it, you can learn a lot and the shifts tend to be a little more relaxed because most partners understand that you do not know where anything in their store is so it will be a little different.

I heard you can call them!