whats your bankroll and risk threshold ?
penny stocks is the easiest way but you can just lose everything. ie, gambling. most people playing that game are losing money long-term.
options and futures is something beginning investors are discouraged from, but it might be worth it in todays market like yesterday was too much of a rise for market. beware that some trading platforms can fukk you up on futures/options, since those are very time-sensitive. any flag/review/unavailability, and you can be screwed.
I dont think playing the market is a good way to make an extra 500 bucks you really need. I think there are better risk-free ways, such as putting your balance on 0% apr credit cards and earning interest on savings accounts, if you really need cash.
for investments or even gambling to work you need a bankroll you wouldn't be worried about losing too much of. in case of penny stocks, its like a poker bankroll.
if you need 50% roi off a few weeks, and you dont mind losing most of your investment as worst case scenario, penny stocks are your friend. look at trends and try to buy, hold and watch it rise, then sell as the pump gets too big. the big thing in penny stock gambling is that you have to be aware that most information coming to you is because the pumpers want you to have it. and the issue is, penny stocks attract gamblers who like to go for big gains (the moon), and by chasing those their chance of getting dumped on gets huge.