He’s in Royal Navy but difficult to date, I think they are post WWII.
The one on his own looks certainly looks to be in Venice, can’t make out the badges on his sleeve or any ship’s name on Cap Tally (band around the cap) if there was one (during WWII they only showed HMS without a name); there’s an another serviceman on the bridge.
The other picture he’s with a Royal Marine in what could be a “dessert setting”, again nothing to identify his rating (RN rank equiv) or ship. Wonder what the tall chimney in background was for.
Being in tented accommodation with marines indicates he could have been serving ashore as part of a Naval Brigade. Seamen gunners, medics, signallers and of course seamen & stokers as extra manpower, often served in shore parties in support of land forces.
You should check for an entry for him in the UK, Naval Medal and Award Rolls, 1793-1972 on Ancestry for the Naval General Service Medal, as second picture could post WWII Palestine. The Rolls don’t cover WWII campaign medals as they are still with the MoD, but the NGSM was an “extra”.