Made my first terrarium. Any tips to ensure its survival?

Hi! Ive recently built this terrarium. Please provide me some tips if im doing anything wrong. Ive put in some Fittonias some moss and a plant thst i forgot the name. So basically i turned my old aquarium into this terrarium as you can see im using aquasoil as a pseudo drainage system for the bottom layer but idk if itll work. Also, ive sprayed some vitamin recommended by the plant guy i bought from as he says its good for the plants to have greenish colours. But idk if its good for any little critters that will spawn in my tank. Any advice would help tremendously. Thanks! Feel free to rate how it looks! ^{^}