The low energy challenge is easy to set up, just make a vanilla world and start playing normally, but always follow these rules:
You cannot sleep in any type of bed (You can still craft and place beds, but you just can’t sleep in them).
You cannot command any blockheads to sleep (The only time a blockhead can sleep is if it collapses from exhaustion).
Eating coffee cherries and drinking coffee is banned
Wearing tin foil hats is banned (You can still craft them but you cannot wear them)