Since no one has simply started a successful planted setup without adding some plants, what was the first plant that you added to your aquarium? Is it still alive today, or did it not make it through some of the trial and error learning?
In my situation, it was a few years ago, the very first set of plants that I added to my 5.5 gallon was java fern and some Anubias (I can't recall the variety sadly). I remember watching them grow and thinking that it was the coolest thing ever, plus my Betta and a few other fish LOVED these plants and at night I would see the Betta resting on the leaves (or inside of the plant hiding away peacefully). It's kind of crazy how adding something so simple can not only change the fish tank in terms of looks, but it can add a ton of benefits (water quality gets improved, fish can have somewhere else to hide, etc.) to your aquarium without that much care.
Ever since that moment, I've always kept various plants inside of my setups ranging from Amazon Swords, Corkscrew and Jungle Vallisneria, different types of mosses, Banana Plant, and more. If you have never tried keeping plants inside of your aquarium, I HIGHLY recommend trying a few low light plants out - you'll never go back!