Buy him a nice pet rock.
And some purple string

If he's reading up he's getting there. Once you know what fish need to be kept alive and happy it's actually pretty hard to give them less. With luck all the fish he has will survive until that time comes.
Also, cories, a betta, and, say, 6 neon tetras can survive in a 10 gallon tank with adequate filtration and proper maintenance. However, with this individual you should advise to get one or the other.