When you open your professions panel, you will see three empty slots for tools that help you gather or boost your crafting skill level. If you go to the AH and look under profession tools, you’ll see what they are for your chosen profession.
The ones in the AH are greens, which then get switched for blue tools that you get crafted with acuity. Don’t worry about the blue tools yet. Look in the AH for the greens and filter by expansion; the drop down menu on the left will get you started.
Herbalism and Alchemy same advice as Skinning/LW. The gathering profs are easy enough. Alchemy when you start has a lot of ‘discovery’ of potions that need to be done. I believe this phases is timegated, you can only discover a few new recipes at a time. Sorry it’s been a year since I leveled alchemy.
Tbh I wouldn’t chose that as my primary prof this late in the xpac, it’s not my favorite, but do your thing.