Please read the official manual, there are lots of expressions that you can use to work with multiple touches. For example, Touch.TouchCount will give you the number of active touches. So if you require two touches to do some action, you can check that Touch.TouchCount=2
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If you are planning to have on-screen buttons to Fire and Jump, this makes everything much easier. You can put a big invisible sprite on the left side of the screen, which will be your RunButton, and then just add these events in your code:
Touch is touching RunButton -> run
Touch is touching JumpButton -> jump
Touch is touching AttackButton -> fire
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