I visited Marrakech recently. The first thing I'd say is don't travel light - take plenty of fresh clothes.
The Medina (old town) is a wonderful sight, but a complete assault on the nostrils. The combination of smells (leather, spices, cooking food, raw meat and sewage) are part of it's charm, but they mean that your clothes can really smell after just a day.
Also if you like to wander around you WILL get lost in the Medina. locals are used to this and will offer to guide you, but they will expect payment and sometimes take you to their cousins shop instead.
Look out for scooters too, they ride them absolutely everywhere. They REALLY don't like having their pictures taken. More than just a privacy thing there are religious connotations, so it is wise to be careful/quick/sneaky.
In the main square in the old town "Place Jamina El Fna" you'll find brightly dressed water carriers by day and performers in the evening, they don't mind pictures but they do expect to be given some change. Look out for pickpockets there too.
I took my M8 with 35mm and 15mm lenses and my film Ricoh GR1.
In hindsight I would have preferred to have something longer with me say a 75mm or 90mm. It's not really my style, but you need to snap people before they notice you. I also should have taken my Ricoh GRD with me so I could have done more hip-shooting, without having to worry about film.
You aren't allowed to take Moroccan money out of the country, so don't draw out more than you're confident of using. Bear in mind that beer is nearly £5 a bottle and not readily available being a muslim country. If you fancy a tipple go for a bottle of wine, at around £15 it represents better value. 😱)
Brush up on your French. Being an ex-French protectorate not everybody speaks English and many restaurants' menus are only in French too.
Oh and good luck crossing the roads - that's an adventure in itself!
I found the light this time of year to be brilliant.
Have fun and I look forward to seeing your pics.
Bob.