Jef, here's a tool you can use to get an estimate of what the resistance will be for a build. Put in the wick size for the outside diameter of the coil (3mm in your case) wire type and gauge, and number of wraps. Pitch isn't very important, leave it at zero or put in 1 or 2mm if you space your wraps, doesn't make much difference to the final ohms though.
And get a multimeter soon. I like those ohm readers that you can screw the atty in to get the resistance.
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And here's a cheap multimeter.
https://www.fasttech.com/products/0/10002443/1179801-best-dt830d-digital-multimeter