I am thinking of buying undervalued stocks using poems platform. How is the brokerage charges for this platform and is it competitive?

The fees of the mainstream brokers are already so low today that they are mostly irrelevant for a Buy & Hold investor.

Your idea that you could successfully identify single stocks that are undervalued and achieve a performance that would be better than an appropriate stock index, is a concept that does not work. Even professional value investor Warren Buffett underperformed the SP500 now over 10 years or more. He himself recommends to the retail investors to buy mostly a cheap and large SP500 ETF, of note.