This is a bit personal. I assume that most people who sit down at their laptop feel good about putting their first words on the screen. Then think about what font you want to use. If you have a traditional publisher, they will usually decide that. That doesn’t mean you can’t use a different font. The most common fonts are: Times New Roman, Calibri and Cambria. If you self-publishing your book, using a POD publisher (Printing On Demand), you as the writer decide. More about publishers later.
I currently write with a line spacing of 1. Many people find a line spacing of 1.15 more pleasant to read. My publisher uses 1.15, not 1. Quite personal, but that doesn’t matter. Experiment a bit until you are satisfied. Again, if you self-publish, you decide everything.
Indentation. You normally start a new paragraph without indentation (unlike books in the English language). An example:
‘The surprise is still on your face, or is that a worried look?’ asks Albert when Buurman has left the office.
‘Both. His analysis of Wolf was sharp, I had nothing to add to that.’
‘His blackmail attempt between the lines, too.’ He walks to the coffee machine and pours a cappuccino for both of them.
This is the start of a new paragraph. Albert says something and the sentence continues on the second line. The second person answers. Then indentation is desired. Then Albert speaks again and there should be another indentation. But because the second person does not speak a second time immediately, the sentence continues on the next line without indentation.
Finally: chapter division. How many pages can a chapter be? That depends entirely on the story. In my books I assume a maximum of twenty pages. That is quite long and half or even less is also good. There are also many different methods to indicate a chapter, such as a number, a name, Roman characters, a place or area or whatever you prefer to use when announcing a new chapter.
Keep one thing in mind: stay consistent. Before you know it, you start with the font Cambria to come to the conclusion that you are using Calibri chapters later. Also. with indentation. Always the same. Check that every now and then.
More next time.