Hey, Rich. Welcome and glad to have you looking into planted tanks. I'm a pretty new 'veteran' at 5 years, 4 tanks. You can search out my threads for how they look, and a total rebuild on a 65 gallon.
For smaller tanks, substrates such as Eco-complete, Flourite, or the various Plant/shrimp substrates are great. I firmly recommend Ecocomplete and Flourite. I've had great luck and they're easier to deal with.
CO2 really is the limiting factor in good plant growth. Yes, you do have to have bright light and good fertilizer, but you'll get disappointing results unless you supplement carbon in some way. CO2 injection's the high-tech way. Liquid carbon supplements (such as Excel) also do help and can provide excellent results.
If you're going to do a good plant light (Fluval, Finnex, planted spectrum, just as examples), and simple fertilizers (Flourish, Flourish Trace, maybe Excel), your can grow things like Micranthemum "Monte Carlo" and Dwarf Hairgrass and Dwarf Chain sword.
In lower-tech tanks, wrapping driftwood or stones with java moss or other types of moss can give you an interesting effect on the floor of the tank without being very demanding. I also have had luck with Dwarf Sagittaria as a low-light, low-fertilizer, no-CO2 plant that will spread and carpet the bottom of a tank. They can sometimes grow over 3-4" tall, though, so it's not really a carpet in the traditional sense.
If you have a good local fish store, or even places like Petco/Petsmart these days, you can get relatively inexpensive plants. Try them out and see what works in your tank.
I highly recommend the forums for research. Build threads and the planted tank forums have TONS of good reading. I also strongly recommend looking at the plant profiles on the Tropica website:
https://tropica.com/en/plants/
Select 'easy' and you'll get a list of stuff that can grow under lower-tech conditions.
Ultimately, you've got to know your own set up: water hardness (in general), light level, substrate, fertilizers...and just try stuff out. I've had horrible failures with some plants that others are getting to grow with NO trouble. All part of the game with planted tanks!
Folks on this forum are amazingly cool about offering tips, advice, and help. Feel free to DM me also. I can tell you what has worked for me. I've attached a photo of my very first planted tank with a single low-light LED Mareineland fixture, almost no fertilizers, and Flourish substrate, just as a reference point.
