I don't believe SMOK makes any coils that are compatible with temperature control (that's the Ti, SS and Ni settings), so you're probably using wattage mode. Here's a very brief rundown of some terms so you know what they are even if you're not using them:
Wattage mode: Just controls how much power you're sending to the coil. Turn it up and the vape gets hotter, down and it's cooler. The 'right' setting depends on your tank and coil. If you switch to a different type of tank or coil, you'll probably need to change the setting to get a vape you like.
Here's a tip: most coils have recommended wattage settings printed on them. They're often exaggerated. When you first use a new coil type, start with the wattage set to about 1/2 the lowest recommended setting. Gradually increase your wattage. The vape will get better for a while, and then it will start to get worse. At that point, turn your wattage back down to wherever you liked it best. That's the 'right' setting for you with that coil. Don't worry if it's not within the recommended range - they're just recommended, not required.
Temperature control (TC): Basically, the mod automatically adjusts the power to keep the coil at the temperature you set. For a variety of technical reasons, this only works with coils made from certain materials, and you have to tell the mod which material you're using. That's what the Ti, SS and Ni settings are for.
- Ti: Titanium
- SS: Stainless steel 316L
- Ni: Nickel 200
Priming a coil: Whenever you replace your coil, even if you're using the same type of coil as before, drip a little eliquid on any part of the coil where white cottony stuff shows. Then install the coil and fill the tank. Wait about 10 minutes after you fill the tank before you start vaping. The point of this procedure is to make sure that eliquid has fully soaked into the wick before you turn up the heat. That prevents burning the wick and spoiling the coil right at the beginning.
I hope that helps some. If anything's unclear, feel free to ask about it.