This process can be daunting – but it doesn’t need to be. A first draft is your chance to find out what it is you are writing. It doesn’t need to be perfect. That’s what redrafting is for.
I find that every play demands a different sort of first draft. By this I mean that some plays can be written from beginning to end. Some plays appear more fragmented and are written from moment to moment. Both are perfectly fine. You have to find what works to get you to the end of the play. There is no right or wrong. Make sure you have fun and play!