More and more you see derivative (futures) contract called perpetuals.
Meaning there is no expiration date so, in practice, you can trade them long term.
Yes perpetuals don't expire but Bitmex also has other futures contracts that do expire and therefore one can trade them by holding positions long term. A newbie could easily trade them minus knowing the type of contract they just longed or shorted.
This guide has a list of Live futures contracts along with their expiry dates
https://www.bitmex.com/app/futuresGuide