The Moroccan currency is the Dirham (MAD), as Morocco is a closed Country you will not be able to get hold of the currency outside of the Country. Likewise as you leave the Country you are expected not to take any currency away with you as movement of the Dirham outside of Morocco is strictly forbidden, so it is advisable to exchange a little at a time.
On arrival to the Country there is a bureaux de change in the airports and many of the hotels and banks where you can collect your Dirham, you will be expected to show your passport at many of these.
Otherwise, as you would expect you can withdraw cash from the ATM’s that you will find at most banks. (please let your bank know you are travelling to Morocco before you go so that they don’t block your card.)
In Morocco, cash really is King. You will find that most transactions require cash, if you want to pay at a restaurant with a credit card you must first check to make sure they can handle the transaction.
Euros will be taken by car hire companies and hotels, but do ask at restaurants before you eat as they may not take euros. It is good to carry a few with you for emergencies in any case.