In reStructured text, it will create a paragraph if you leave an empty line. So, this is one paragraph.
And this is another paragraph. And you don't control end of line.
If you want to have explicit lines, there are several ways. One is a literal block::
This is a literal block.
It respects new lines. It starts when you have :: at the end of a line, then an empty line, and
the block is indented.
This is outside the literal block.
You can also use "line blocks", which are often used for things like poems:
| No man is an island,
| Entire of itself,
| Every man is a piece of the continent,
| A part of the main.
| If a clod be washed away by the sea,
| Europe is the less.
You just put a "pipe" character in each line. It will preserve newlines as well as blank space at the beginning of each line.
All this and more in the quick restructured text guide you should read, because it's not actually Nikola-specific ;-)