Short term trading could mean anything from a few minutes to a few days. That is the time frame you want to focus on for achieving your returns. That being said, Your goal of turning 200k in 1 mil in 2 years is unrealistic, especially if you have to ask that question.
Here's the plan, find a mix of strategies that will provide you with the earnings potential while reducing your risk. Create a game plan, execute the game plan, review your results to ensure you are trading optimally, and keeping on target.
You will have set backs, and when they happen, you need to be able to pick yourself up and get back in the game.
Good luck! (It always helps!)