Concrete Footings for 16x24 log cabin

I am buildings a 16×24 log cabin in rural West Virginia. It will not have electric, running water, or any type of HVAC. One of the biggest worries I have, as I feel I should, is the foundation. I am planning to use 18 12" diameter concrete footings (pillars) and have a few questions about doing this.

1. Does anyone know where to find the official frost line for northern West Virginia? I looked all over and found different answers (between 12 and 36 inches) and just want to make sure. Most answers were around 30" so if there is not an official number available I am going to go with that.

2. Do I need to have a flat piece or pyramid at the bottom of the footing? I’ve read that it is totally necessary but have watched multiple videos where the builders did not do this.

3. How deep below the surface can I end the footing at? Sorry if that is worded poorly but I don’t know how else to ask it. I do not want any concrete sticking out of the ground as I think that would ruin the log-cabin vibe but I have not been able to find any info on this. I saw a finished model of what the cabin will look like and the treated 6x6s went into the ground, I’m just not sure how far.

Any insight is very helpful. I am quite new to this but I am determined to make it work by educating myself and thinking ahead.