I would expect the lower leaves to yellow after transplant, so don't be too concerned about that. Remove them when they start to yellow as they will never turn green. I'm thinking you may have overwatered so try to only water once a week if you don't get any rain. Poke your finger into the ground up to the second knuckle. If the ground is moist, don't water.
Newt
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.