There is one other very simple reason this could be happening, so you might as well check it out:
Sometimes the "compose" window gets flipped to the "html" window. If you paste formatted text into the html window (depending on where it came from) you may just get the text itself, without formatting. This happens in other programs too: it remembers the last mode you were in, so if you clicked on the html button for any reason (even by accident) it may stay there for all future posts, until you click the compose button.
Otherwise... the problem could be that, because you don't know html, you are treating the website too much like a word processor -- which is a very bad idea with websites. With paper, you control every detail of where things appear. With a website, you have to create a layout that is compatible with many many different kinds of devices and software, and it will look very different on each of these.
Even with Wordpress, you don't want to format paragraphs in a word processor and then copy and paste. Don't use indents. That's something which, in the internet world, needs to be done with advance coding skills -- you need to use a style sheet. And generally even then, it's not recommended for the web -- just for something more controlled like an ebook.
When you do that kind of formatting -- in a word processor and then paste -- it sometimes looks okay to you, but I guarantee there is something hinky with the code, and it will look awful to some of your readers. So, if you don't know how to code, don't do any formatting in a word processor. Maybe italics, but even there, weird stuff can happen.
In the meantime, your problem with naming your page.... is it possible that you have an earlier draft of that chapter in that directory? Blogger tends to change your title when there's already something with that name. If that's not it, then you can change the permalink name in the post settings column on the right of your screen under "links." It will way "permalink ?" and give you what it would automatically call it, and underneath that you can change from automatic to custom permalink, and then put in what you want. (You JUST put in the part you want that page to say, not the path or the .html. So you'd put in "chapter-66")
It's also possible that you somehow have some invisible character entered into the box where you put the title in, and Blogger is inserting the code for that -- but that usually involves and ampersand, so it's not likely.
(BTW -- The new Blogger does seem to have trouble with ampersands. It's driving me up a wall.)