Thunderbolt 2 to Thunderbolt 3 adapter

The Thunderbolt 1and Thunderbolt 2 cable are the same, so a TB2 cable up to the 2015 macs (with the mini-displayport/Thunderbolt port) works fine on your TB1 Mini. Be careful when cable shopping though because unscrupulous sellers will try to pawn off a mini-display port cable as a Thunderbolt cable. The thunderbolt 1-2 cable will work as minidisplay cable but a mini display cable will not work to transfer TB data. Good luck!

Pretty much the only thing you can use Thunderbolt 1 for is attaching a display. The same almost also hold true for TB2 except if you're going to a TB3 device.