Connecting MacBook Pro Retina late 2013 with Thunderbolt 2 ports to USB-C hub
Don't confuse USB-C the port with USB 3.0 the protocol.  The Apple Thunderbolt 2 to Thunderbolt 3 adapter will connect to USB-C hubs, docks, and devices with a USB-C port and supports the Thunderbolt protocol.  The TB2 to TB3 adapter does not support the USB protocol and does not provide power.
I've seen people report that a TB3 dock will support USB 3.x (USB 3.0, 3.1, and 3.2) devices when the dock is connected by a TB2 adapter and cable.  The dock must have a USB-C port, a female receptacle, and not a USB-C jack, a male connector, for this to work.  USB 3.x docks and hubs often have a captive cable (cannot be removed without breaking something) with a USB-C jack or a micro-USB-B receptacle.  USB 3.x docks and hubs with USB-C ports exist, but are rare in my experience, and will not work with the Apple TB2 to TB3 adapter.
If your MacBook Pro has USB 3.x ports then use them to connect a USB 3.x hub or dock.  If there are no USB 3.x port then you can use a TB2 to USB 3.x adapter to gain those ports, these adapters will have USB-A ports and not USB-C ports.  Adapters to turn USB-A ports to USB-C ports exist but break the USB spec, using them can damage equipment, or simply not work as desired, and so should not be touched.
The Apple TB2 to TB3 adapter does not support DisplyPort so if you intend to plug in a USB-C DP display or adapter then you need the right kind of DP cable or dock.  There are TB3 docks that will support DP displays but not necessarily with the TB2 to TB3 adapter.
There are USB 3.x docks that will support video out with a DisplayLink chip if there is a desire for video out from the dock.  These are separate video chips from the one in the attached computer which comes with it's own pros and cons.
I know that's more than you asked for but I've seen questions like this before and I'm anticipating follow-up questions you are likely to have.