NEED HELP

im writing a nove called "The Deafening Rainfall" and when i post it everything is jammed together and all the spaces go away and im not sure how to use the pre button

"THIS IS A SENTENCE"

would i highlight the sentence like the example and press pre or would i have to highlight the space before it?

or am i completely wrong and tell me how to do it because no one wants to read my work because its all cramped together without spaces or indentations.

please help if u can.

Aye aye aye, neglect for the rules....
NO LEET

Anyway, I don't think that pre whatever works... I seperate paragraphs with the enter key and if I have enough time and am really bored I space it three or so times.

Like this...

or this

Or perhaps I could even do this.

But that's an entirely different subject...