You'll need to read the lessons here, and maybe a book or two as well, to understand how this works.
It's possible to start with as little as about $50, but if you trade with a small account, don't look at it as a way to make money.
Very, very few new traders manage to make profits, and almost none make more than 5% per month. Eventually, after years of practice.
So for every $1,000 in your account, you might be able to make $50 per month from it. Maybe even a little more. If you end up in the small minority who become profitable.
I'd look at Oanda's platform. They have two - Metatrader and a much easier one which is good, and as intuitive as any. That's also a good place for a very small account. But you're a long way from live trading for money at the moment. I hope.