As ZxC noted, it’s important to figure out what you’d like to do regarding CO2, lights, and fertilizers. I usually don’t dose CO2, run basic lighting, and the only ferts I use are root tabs.
Personally, I find the easiest plants for low light tanks are java moss, java fern, and anubias.These plants are fantastic because they’re not demanding when it comes to light, and they’re very versatile in how they can be planted. Java moss can either be floated freely, or attached to decor with clear fishing line/beading thread/cotton thread or glued down with superglue. Java fern and anubias are both rhizome plants. The rhizome, a special part of the root system, must not be buried or the plant will die, so they can either have their roots planted in the substrate with the rhizome exposed, or tied/glued to rocks, wood, or decorations.
Some kinds of crypts (usually the wendtii, Which come in red, green and bronze), water wisteria, water sprite, and Brazilian pennywort can also work well. These are not rhizome plants, so you can plant them directly into the substrate. Pennywort can also be used as a floating plant, and doesn’t necessarily need to be planted.