USB C to USB C Cables
You will need some USB C to USB C cables. You can use these to charge the device and to connect to other USB C accesories.
Here's another area where we suggest going straight to Apple. You can use the official Apple USB C charge cable to connect USB C devices to your MacBook
2-Meter USB C Charge Cable - $19 at Apple
Apple also sells a Belkin Thunderbolt 3 cable that looks like a USB C cable, but it actually supports faster data transfer speeds when connecting Thunderbolt 3 devices. If you are using these devices, you should purchase one of these cables instead.
0.5 Meter Thunderbolt 3 cable - $29.95 at Apple
2 Meter Thunderbolt 3 cable - $69.95 at Apple
You don't need a Thunderbolt 3 cable to connect to standard USB C devices, even though the connection looks the same. A Thunderbolt 3 cable allows you co connect up to daisy chain up to six Thunderbolt 3 devices.