I would have to look up the exact models but yes sub usually means sub ohm.
As for settings. On a REGULATED device (specifically one with protection circuits) what I do is start around 14 watts for a .5-.6 ohm coil and then just bump it up .1, vape, bump it up .1 vape.... keep going until I get a taste I don't like then back it down.1. Really you can do the same with higher ohm coils you just might find you need to start in a different place.
I know Kanger coils have a suggest watts range printed right on them. Maybe what you have does as well. Just start at the bottom and work your way up until you get the vape you desire.
Be sure when you order that you get extra coils and possibly a second tank. I would tell you a second mod if you could afford it. Backups are key especially when first starting out.
I run Kanger subtanks/toptanks but I use the rebuildable deck that comes with them (you can do either rebuildable or purchased coils with those tanks) So I don't have to worry about running out of purchased coils. I just wind a new one if I need to.

When I was running purchased coils though I typically went through 1 -2 a week depending on how cloging the juice I was vaping was.
Edit : I don't know a whole lot about those tanks in particular (I can look them up if you don't know) Do they have adjustable airflow? If they do then just open up the airflow for a more airy draw. I run my subtanks wide open.[/QUOTE
I keep mine wide open too. The tanks get crazy hot. I'm gonna have to use these vaporfi sub ohm as back ups for now. Maybe I can sell the one that's still packaged. But I'd feel a bit guilty, unless they were already familiar. I'll have a look at videos for both, and availability in au. But I don't want subohm. The technology and number of choices went from 0 to 100 over there, while I've been down under at a standstill. Ta I went thru this the first time trying to choose, there are so many with so many options it gets to be too much.