Thanks in advance, I just bought a 20G tank and im wanting to set it up as a live plant aquarium for various fish, im looking for info on which soil,substrate and plants to use once all that is done then I will figure out what fish I want to use and also what nutrients I should be looking into. again thank you in advance.

I would choose either Eco-Complete or Flourite as a substrate. Both are very popular with aquarists. I don't have a strong preference, but I think a lot of people prefer the Eco-Complete.

There's many nice small plants that would be good in a 20G. Nana anubias, micro sword, wisteria, java fern...you could probably add a few others in there. I always recommend java moss too, just because I think it looks cool and it's so easy.