Port Said is a place where you can wander around in relative safety but there is little that I found to do there except enjoy the atmosphere, in all senses, of Egypt and look at the squares and houses which have a certain, if dilapidated charm. If you need the loo or a drink then use the hotels, there are a few there. The start of the Suez canal is there but is not overly-interesting as there are no locks on the canal. You will find that running the gauntlet of the vendors as you return down the narrow causeway to the ship a little daunting.
Alexandria however is an entirely different kettle of fish.
Best if you can get a small group together, six is ideal, and go into the car park by the dock, negotiate with the taxi/ combi drivers at the top right end just outside of the gates and tell them you want to go to The Catacomb of Kom El Shokafa first and Pompeii's Pillar, then
Alexandria library, then Montazah Palace then Qiatbay Fort, if you are up for it try an Egyptian restaurant/ café for lunch, we did and never suffered any ill–effects only enjoyment. We finished off with a drink on the roof-top balcony of the Cecil Hotel and had a great view over the bay and watched the hair-raising antics of pedestrians and traffic. Cost… about US$25 each (plus food, a pittance).
There are tours you can book around Alex with “Castro” on the net and I have heard good reports of these.
Look at the Alexandria tourist web sites and familiarise yourself with this intriguing city. Regards….. Neil