Macbook Pro 13 Retina Display - storage

Hi everyone

I´ve been reading some reviews about the new version of the Macbook Pro 13 Retina Display released in March 2015.

It is not clear, but it seems that the only option for external drives is to buy Thunderbolt enabled ones. Is this correct?

I have a 750GB USB Western Digital external hard drive that I would like to use. I could format it to the OSX system (I´m new to Macs, hence my lack of confidence in this topic) and use it, just would like to know if it´s possible. Is it the same with USB sticks?

I dont have a problem if it´s slow speed, it´s just for back up reasons.

Thanks.