Guppys and CPDs will get on just fine.
Your plants will need some additional nutrients to survive. They will also need enough light.
You can and should remove the plants from their pots; remove any lead weight and plant them deep into the gravel (gravel is fine for many aquatic plants. Also be aware there are some plants that you don’t plant into the gravel like anubias and java ferns – these are best tied to a bit of bog wood or stone.)
The best thing you can do for low mantainance plants is add some root tabs and then use a good liquid fert every other day or 3 times weekly (TPN+ is excellent).