HomePod mini can be connected to any USB-C charger. If you want to have both on the same power supply, there's this one, for example, which I'm very happy with: Aukey Omnia PA-B4 GaN Charger (65 W, Power Delivery 3.0)

A 20W USB-C power adapter is included in the scope of delivery.

Power supply? You connect them via wifi and Apple HomeKit app.