@OP -
Goto the swamps and attack bog things. They drop regular, red, blue, and yellow seeds. Through selective breeding, you're able to cross-breed the plants and eventually get bright plants which produce resources. I would highly suggest getting fertile dirt from corpsers in the swamps or ant lions from the solen hives. You will also need a ton of water. If you have a house, make sure you purchase a water trough to refill water pitchers. Lastly, you will need greater potions to help cure your plants from diseases. Find me in game if you need help getting set up.
If you're in need of plants, check out the 1CE Vendor house. I have a vendor set up selling decorative plants all day for 1K/plant. Also if you need seeds, I have enough to sell, as well as potion kegs for sale @ 35K/keg. Dirt's usually gating now late at night at Brit bank. If no gate is available and 1CE members are on, just ask them to page me and I'll get you all sorted out.