If you're British, Australian, Canadian or from the USA, you won't need a Visa for Morocco.
If you aren't from any of these places, check online whether or not you need one. If you do need one, you could ask the people at The Visa Machine to help you.
Strictly speaking, you are not required to have a motorbike license to drive these pint-sized bikes around Morocco, nor do Moroccan bureaucrats insist that you carry an International Driving Permit. But we would recommend having an IDP anyway. And remember, this is used alongside, not instead of your license, so bring both.
When describing the particulars of the event, it would be worth checking your insurers are aware of your driving qualifications. It might be legal for you to whizz around on a 50cc bike in Morocco on your license - but maybe not in your country of origin, this could be a factor in your insurance quest.