Before discussions about plot, character development, and pacing, let's start with the software. If you are serious about being a writer you have to hone your computer skills.
Way back in the beginning, computers had punch cards. I don't personally remember those days, but I have seen the punch cards. It is basic. Binomial. A collection of zeros and ones in groups of eight or sixteen. (I'm going on memory on this. Research it if it interests you.)
Fast forward to today. If you learned to use a typewriter (boy, are you old!) before you transitioned to a keyboard, you need to throw out most of that knowledge except for the letter placement on the keys.
Computers use codes for their instructions on character placement. You don't have to learn coding, but you do have to understand the functions of the software. Remember the saying: garbage in, garbage out?
If you want to center the title, use the center function. Do not use the spacebar or tab key to eyeball where the center mark is on the page.
The same is true with indenting the first line of a paragraph. Do not use a random number of spaces (spacebar), use the tab key.
The same is true with the end of a line of text, let it wrap to the next line. Do not use the enter key. Set the line spacing to double spaced lines.
The same is true with starting a new page for the next chapter. Do not use the enter key to go down the page until you reach a new page. Use the page break function.
Unless you use the correct procedure to center, indent, or start a new line or page, you can expect the results to be fluid. If you want them fixed in position, you have to use the correct function. I want them in fixed rather than floating/fluid positions.
If you don't know how to do these things, then take the time to learn them. One way is to go across the menu bar and see what each item on the dropdown menu does. Watch YouTube tutorials. Buy a book and follow the instructions on your computer.
I prefer mss that come from a computer, desktop or laptop, rather than from a tablet (any brand, but expecially not those that require converting the file into MS Word).
If you expect Cactus Rain Publishing, any reputable publisher, or literary agent to take your work seriously, fund it, and add it to their catalogue (reputation) then you have to be serious about the format of your work.
It is that simple. Write right. Have fun.