I have a second floor restroom at my workplace and there is a little bit of water backing up and some sewer gas smell. There is rarely anything that goes down that drain but there is a little water in it that I can see. Also it seems that the urinals in the same restroom are draining very slowly. There is a lot of pumbing and drainage piping so do I have to start snaking or start opening some cleanouts?

You're going to hafta snake out the drains to clear them. The urinals may have to be pulled and thos drains snaked as well. Good luck, Tom