Botany is harvesting materials in the field from trees or plants. It's basically an agriculturalist. The game has Miners and fisherman. so from those 3 jobs you can collect items then you will need to be a certain crafter to make stuff from those items. it's a lot to take in so i would suggest pick a class that can battle and level that up and you can see what weapons you use and what repairs it then pick that crafting class.
Also in every town you can buy the lvl 1 weapon or tool for every class.