Hi, Vertigo is a very nice hotel, located in a very good location could be said just right next to central station, you gonna like it.
Marseille is a very beautiful city. Also take a trip to other nearby places and you will have a memorable experience. I do not know how long you plan for travelling but if possible also suggest take a trip to Corsica. There is a night ferry to the island, and also back to mainland France. The island is absolutely breathtaking.
One general tip would be then take very good care of your belongging. Marseille is not very dangerous city, but not a very very safe I might say.
Wish the advice helpful.
Enjoy,
Kritin