Talk to me like I’m stupid (I am)

I am on the hunt to start a live tank to give my betta fish, Fu, a better life. He’s doing very well where he is, but he deserves the best.

I want to start a 20 gallon tank with live plants. I know about cycling for weeks so depending on when I get my tank, it may be well into the new year when I can actually change him into the new tank. I don’t want to go into it blind though.

I love the idea of: - a mix of forefront hardscape and background tall live plants - using some of the statues I currently have if they’re okay to include in a live plant tank (if not, I’ll keep them in my original tank which I plan to run as a back-up) - I love the look of top-floater plants but I’ve been directly told duckweed is invasive; what’s a better alternative? - beginner in-ground plants for someone dumb like me - a dark “witchy” type aesthetic if possible, any reccs on plants or how to hardscape for a moody dark aesthetic is appreciated

Fu has tank mates he is at peace with, but I’m unsure if I’ll transfer all them over so for right now this is a betta-only plan.

Thanks in advance! ❤️