Can I make this wooden box into a moss terrarium?

So, i have this wooden box, and i really want to make it into a terrarium.

But i have a few questions.
What kind of coat/sealer should i put on the wood, so that it wont rot? I was thinking some epoxy or something like that, but I'm not sure which is best?
Also what kind of soil is best? I want to have the walls coverd in moss, and maybe a few stones on tree branches, but since its on the wall, i assume it must be soil that i can kinda "mold" (if that makes sense)
And i plan on taking the rope out, and then theres 2 small holes i thought i could place led lights in, and if necessary, make the holes bigger. So if anyone has any recommendations for what kind of small grow lights would be good, i would really appreciate it.

Youre welcome to give me other tips or ideas.
and youre also very welcome to tell me that this is a bad idea and that it will never work lol.
(Sorry for my english, english isnt my language)
(Also, the last picture, is kinda how i want it to look inside the box. Like the bubbly moss and the decorative stone/tree