1.Moss Needs:
Moisture
Shade
Air
Easy enough right? The beauty of this plant is that it grows in acidic soil and doesn't even need soil. Soil really helps though. Someone right now is growing moss on baby diapers because they hold in moisture and allow the moss to grow.
2.Grass Needs:
Moisture
Soil
Light
The best grass you can get for your tank would be the grass that grows on the road and in the cracks. Take a few heads off the grass and bury them. They sprout fast, just a few days keep soil moist.
3.Some things you might need for a tank:
Mist bottle + Neem oil (gets rid of bugs) + Water
Pair or small scissors
Mist your tank 2x a day and watch it mature and stabilize into a very green tank. I want you to take a picture of it and show me it please.

You can solve all your problems in a garden/laboratory.