Three important things.
1. You want at least 6500k lighting for a 5 gallon tank. LED lighting will probably only support low light plants unless you want to upgrade lights.
2. You can buy substrate just for plants like eco-complete, flourite, aquasoil, floramax, etc. Or you can go with regular gravel/sand but you will most likely need to use root tabs if you are planting heavy root feeders.
3. As others have mentioned I would go with seachem flourish comprehensive and if you're doing low light co2 is not really needed. If in the future you decide to do co2 you can get seachem excel, pressurized co2 system or DIY co2.
Some good low light plants are java moss, java fern, marimo balls, and banana plant