I feel like my story would be too long and can not be complete in time. Can I leave it at a node that solves most plots but still leave some suspense, like only finish the season 1.
That sounds very interesting! I'm sure as long as you have some moral/philosophical/ethical/etc dilemma in the story that gets addressed, then I'm sure it's okay. Are you going over the word count limit by a lot?
My story was almost 2500 words.
No, I wrote 1700 and realize that should be 1/3 of my story, so I am thinking just submit it as the first part of a trilogy.
That sounds really interesting. I'm sure it works the way it is, but like would it be possible to strip it down to the plots that you're closing and not leaving for the other two parts?
Sure, that seems fine, as long the story has at least some kind of closure/ending, and doesn't just drop off in the middle of everything.