Good Day,
I would suggest a copy of "Natural Reef Aquariums", by John H. Tullock,
chapter 2. There is a step - by - step for a 20 gal. "beginner tank" with
complete shopping lists and references. (along with any other books that
catch your eye.) After that more questions can be posted.
>cheap.
Also I would suggest mail order for most of your "hardware" and maybe even
the "software" if local livestock isn't available or doesn't appeal to you.
A rule preventing students from bringing in new specimens "for the tank"
along with "hands out when not maintaining" stressed from the beginning
might be helpful.
just my .02
Jim