Hey there.
I’ve just done my once-a-decade upgrade to a mac pro laptop… it has only two USB-C connectors. I will only use it for disk mode & using OctaEdit. (and the Digitakt with C6)
I’ve tried a combo of a brand new USB-C > USB (flat) cable with a USB2 (square) adaptor and it’s not working.
must it be a USB-C cable with a USB2.0 (square) adaptor OR
USB2.0 (square) cable with a USB-C adaptor ?
totally confused! Thanks 
So I’m not sure exactly what MacBook you have, but my friend has a MacBook pro probably about as old as yours and it only has USB c and we regularly plug my USB interface into it to record.
He uses dongles that go from USB 2 (or b? The old style rectangular one that’s in all laptops, computers etc) to USB c. So look into buying one of those.
He recently brought over a little USB hub thingy. He plugged it into one of his ports and it had two USB slots, hdmi, other stuff. Look into that.
I just got a new MacBook air after 8 years. I went with the Kingston nucleum dongle. Tons of connections and not too outrageously priced. Aluminum housing and looks nice too.
Wow. Looks super handy that one.
so for example you plug in your Octa - with the original red cable? - into the USB port on the donglke and it works fine?
I have a cable with a USB-C plug on one end and a USB-B (square) plug on the other. Works fine. I figured everything will switch to USB-C eventually, so might as well buy specific cables rather than using adapters.
This is exactly what I need to know - thanks
I was wondering if such a cable existed. I opted for the dongle, which is also plug and go.