~snip~
Of course, if he makes only $3 profit, that probably won't even cover the fees for buying and selling bitcoins, but he will still make a profit. And learning to trade from scratch with $30 will most likely result in him losing the entire $30 altogether. I can quite possible to advise him to buy bitcoins, especially in a downturn, but I personally would not dare to advise anyone to start trading, the risk is too high.
Yeah, trading is expensive, and most people will end up losing money, plus the fees are constantly there.
With $30 OP should focus on learning about Bitcoin, lightning, etc, it's a great opportunity to move Bitcoin around. At the end of the day it's the same if OP was moving millions, so better to learn with less money as mistakes would cost almost nothing.
I wouldn't focus on trading, just on learning the tools of Bitcoin.