One thing I find helpful to determine texture, is to pluck off a few hairs (newer, shortish hairs are best to use). Hold each one at the root, and hold it sideways, parallel to the ground. If its coarse, it really just sticks out and doesn't bend much. If its fine or normal, it bends and hangs straight down. It's hard to distinguish between normal and fine hair really, but by rolling a strand between your fingers- if you can't really feel much substance, it's probably fine.
My grays are coarse, everything else is normal.
Here's a link for determining porosity and density that shows a different technique I had not seen before:
How to Find Your Hair Porosity and Density | Curly Nikki | Natural Hair Styles and Natural Hair Care
2C/ Coarse/ Normal porosity/ SW Florida/ Transitioning to gray
Cleanse: CJ Daily Fix, JC Cleansing Cream, TJ Tea Tree Condish
Condish: JC Too Shea, CJ Curl Rehab (both as RO & LI)
Stylers: UFD CM, CJ PP, JC Spiralicious, Darcy's Cream Gel & Cocoa bean whip