asks: How do I know if my story is too long? I tend to write way too much and I'm worried it'll seem like a lot to take on. Should I split the book in two or leave it as it is? I also have the same question for individual chapters.

If you're considering a series, then be sure to read Question 5: Writing a series. It talks about the different kinds there are, and includes a section to help determine if your story needs to be a series or not.

Regarding individual chapters, this is a personal preference for authors and readers alike. Take a look at Question 41: Chapter length.

As for writing too much, I can offer a few guidelines. "Writing too much" is kind of a subjective term. Some stories will take longer than others to finish. But it's possible that "too much" could mean excessive description. If the pace is dragging because all the backstories are being drawn out, or all the scenery is being described in great detail, then that might be too much. Refer to Chapter 13: Tailor Your Description as well as Chapter 15: Ease Up on Backstory for more information.

Assuming you're not writing excessive details, how can you tell if your plot is simply too big for one book? Word count might be helpful. Most novels fall between 40,000 and 80,000 words. Some reach 100,000. A few get even farther than that, but over 100,000 you might want to start thinking about whether the story can be broken up into individual chunks or not.