charging apple watch se(1)

Essentially any Apple power source and cable that fit into the connectors at either end are compatible and safe to use. There will be performance differences, with USB-C faster than USB-A to charge, but they will all work. The "charger" for an Apple device is built into the device. It is not the thingy that plugs into the wall, and it is not the cable that connects the thingy that plugs into the wall to the device. They are just a source of current and a way to get it to the device, respectively. For more info, see:

When to charge your iPhone or iPad - Apple Community