Jacob,
This answer may be too late but you should remove the plants from the pot. I generally prefer to buy these as bare root rather than to pay the premium for the pot. The substrate should be fine and ideally include some iron. A simple way to accomplish this is to add a product like API’s Laterite to your substrate. The use of a substrate heater is also particularly beneficial to Crypts as it will create a flow of water through the substrate which will bring more nutrients to the roots.
You can offer a variety of foods to S. vaillanti. This species is the easiest to feed and breed in the genus. I have bred them on a diet consisting entirely of Ocean Nutrition’s Community Formula flakes. I would suggest a mix of flakes, pellets, frozen and live foods.
Best of luck,
Mark