What is the perfect tank set up.?

I have a 40 gallon with fish and ornaments in it, but the don't look cool so I want to change it. I was thinking red or black or a mixture of both rocks. But how many and wat kinds of easy plants should I get. I don't feel like buying more lights so I'm using the ones that are on it now. There are to lights that were meant for a 55 gallon. Idk how strong they are but theylll be fine! Again, what are some easy and thick/ tall plants . And how should I set them up