@Kidcoder12 Well, I only started writing, but I think it's important to develop characters with both strengths, weaknesses and flaws, and with aims and motivations. Also, try to avoid clichés (overused plots).
As for grammar, the most important thing in my opinion is to add paragraph breaks (start a new paragraph), especially when a new person speaks in dialogue. Also, it's a good habit to read over your story to make sure it makes sense.
By the way, I really enjoy your writing style. For better tips, you could search up "writing tips" or something, as I am not very experienced.