Watts, the number with the big W beside it tells us how much power is being sent from the battery. The higher the watts the more juice is vaperized though at some point heat is increased and the higher the watts the shorter the battery life as its draining faster, adjust watts up and down to find your vape level but this you probably know.
Ohms is the lower number on left of screen followed by ohm symbol that is kinda simlar to the letter Q. For rebuilding, which is your question, this is the important number. It tells us the resistance of the coil. Important, more so if you don't have a seperate ohm reader.
The Kanger Mini tank takes 1.5, 1.2 or .5 kanger factory coils. If, for example, a person first used the 1.2 then .5 coils ,which I think the kit comes with now at least mine did, and decided they liked the vape with the 1.2 coil then when wrapping a coil for the rebuildable deck a person would want to do enough wraps to get the ohm resistance to 1.2 so they get a similar vape experience or vis versa.
Volts is the upper number on left followed by a V. It will read 0.0 V until you press the firing pin. Can't see it while vaping so just fire your mod while looking at screen and it will show the volts.
The watts, volts and ohms work together called "ohms law" to determine how many amps is being drawn from the battery.
Ohms law is critical to understand when useing a unregulated mod so the battery doesn't vent/explode
The Kanger subox mod is a regulated mod so it will refuse to fire if a unsafe situation involving ohms law is created. Regulated mods brought safe vaping to the masses. I understand your confusion as I didn't understand this stuff at first too. That's what is great about regulated mods such as you have. Wrap a coil to the ohms we want and safely vape away until battery gets too low then change or charge battery
Use following link to determine how many wrapps to do to get to your desired ohm resistance. Play around with it by entering different gauge sizes of wire, 26, 28, 30 and change up the coil diameters to get familar with it. After a while it will start to make sense.
Coil wrapping | Steam Engine | free vaping calculators
The lingo and terms had me quite confused when I first started but after awhile it will start to make sense and please post any further questions. We are here to help. Some reading in the coil thread might be of worth to you also.