You can travel independently or use an organised tour trip, I went on one 19 years ago which took you round the highlights including the city wall, part of the countryside, I think food was included (but do ask) and various shops which interesting enough don't buy anything tho.
You can book at Algiceras port direct, travel shops or through your rep.
The second language in Morrocco is French not Spanish which may be useful.
I travelled independently to Ceuta wasn't wasn't a problem, an interesting city in it's own right originally Portuguese before Spain got it.