Can I connect LaCieMobile Drive with USB-C to my Macbook Air USB3.0?

All the LaCie drives I bought came with two cables: one for USB-A and one for USB-C. All you really need is the proper cable and if you bought the drive new and it is missing the USB-A cable you need to contact LaCie.

If the drive is not new or you lost the cable they're likely available at many web stores like newegg.com and others.