A list with things you need for increasing Gathering.
Remember to have right tool equipped and energy to do the action.
Finding new things and increasing your Knowledge gives you more XP then going for same item over and over again.
Bushes, Fruit trees, Wild Herb, Shrub and Thicket you can use your hands
Meat you need Butcher Knife
Hides you need the Tanning Knife
Wood you need the Axe
Blood and Sap you need the Fluid Collector
Stone and Metal you need the Pickaxe
Wild Herbs and Crops need Hoe
Empty Bottle to collect Water
All tools can be bought from Zaaira inside Velia.
A good place to get Iron and Copper are Coastal Cave (Left side of Velia) near the Node manager Egrin.
Potatos are straight up from Mariano the small women woth the cat on the roof.
Next to Work supervisor Santo Manzini you have a few Fruit Trees.
If your planning on crafting and cooking, this will come eventually.
Not sure Fishing counts to Gathering, since it has its own XP