Currently the most popular EDC notebooks are the Rite in the Rain notebooks and the Field Notes set. The problem with the Field Notes notebooks imho is that they are pricey for what you get. They're about 3 notebooks for about $15. There are some alternatives you can get for a fraction of the price.
Items discussed:
Moleskine Cahier Journal, Soft Cover, Pocket (3.5" x 5.5") Ruled/Lined, Black, 64 Pages (Set of 3) ------------- $9
https://www.amazon.com/gp/product/8883704916
Maruman Memo notebooks (These fit in pouches better)
https://www.amazon.com/gp/product/B00T9CHYZO
Rhodia notebooks
https://www.amazon.com/s?k=rhodia&i
Gerber Chonk ($25)
https://www.amazon.com/Gerber-Gear-Chonk-Multi-tool-Equipment/dp/B0BNWF893W