I've been twice in Decembers pre-Covid, and enjoyed it (mostly) the first time, but hated it the 2nd.
An English friend (that lives and owns a riad in the Kasbah there) showed my husband & I around the first time and gave us a few tips.
One was not to eat in the main Djemaa El-Fna square of an evening, as there's obviously no running water for hand washing / washing up of plates etc., between customers. Mostly involves not much more than a dunk in a bucket.
He also said that regarding the souq & street hassle (being called at to buy and so on) it's perfectly acceptable to just walk on and ignore, otherwise they will persist.
It felt rude at first, as we have been to other countries where a polite "no thank you" sufficed, but some of the people in Marrakech are relentless. The mainly male sellers will often grab you and expect you to buy something just for making eye contact!
The women hawkers in the square are particularly handsy too & rather aggressive at any refusal!
The 2nd time we did more things on our own. To avoid my cross-body bag being tampered with, I kept it inside my closed jacket. But a man just tried picking my pocket instead!! Hope he enjoyed the snotty tissue. I hated the fact that I was targeted in that way though.
We walked past one shop outside the medina, where the owner seemed relaxed and friendly, he said there was no obligation to buy, but then became quite unpleasant when we did not.
There are so many scammers. I found it exhausting being on my guard all the time, and not being able to take photos freely, or look at our street map without unsolicited help (always involving wanting money, or a diversion to a cousin's (stinky) tannery instead of our intended destination which we were informed was "closed" that day. It was not.).
Wouldn't recommend a horse carriage ride as they spend time on streets full of thick traffic fumes.
Do be prepared to see things from Moroccan culture that cannot be unseen (mostly involving animals).
There are of course some interesting and more peaceful places & things to see within the city that others have mentioned, but for me personally, Marrakech is generally just 'too much'.
Take care and I truly hope you enjoy more than I did, OP :^)