If you have not proven yourself to be profitable on equities yet, I would not start day trading futures. Maybe you should be on a sim before making a transition.
Yes. You can join a proprietary trading firm. You will need to pass the series 56 or series 7 test. You can then bring in just a few thousand and day trade US equities all you want. Depending on the firm, they will leverage you around 10 to 50 times your money.
+1 I made the switch to futures after trying to trade stocks for more than 10 years... There is absolutely no comparison. So many advantages point in favor of futures... Daytrading stocks is futile, no wonder stock traders are a dying breed.