Hi Alice,
I can only recommend that you take a look at the USB Type-C Specification, as a source of truth.
You will see that your are in a situation not so dissimilar to a “USB Type-C to USB 2.0 Standard-B Cable Assembly”, except you don’t have a data USB Type-B connector at the right end, but a power only magnetic connector. So you should place only one 5.1k Rd resistor on the CC1 line on pin A4.
When it comes to current, the same specification requires a Type-C supply to be able to deliver at least 500 mA. And for voltage, the Universal Serial Bus Specification Revision 2.0 defines the valid VBUS range between 4.40V and 5.25V.