Hi again @Hickory,
Markdown uses standard HTML, so to add an extra space, use
as in the following example:
Your` `text` `here
Don't use the quote marks, and put a ';' after each (I couldn't get this system to just let me type that!) You can put as many in sequence as you like, each adds a 'non (line) breaking space'.
Centreing is just as easy. Use the style "text-align: center" as follows in any tag (note US spelling of 'center'):
<div style="text-align:center">This text will be centred.
<p>So will this paragraph.</p></div>
<p style="text-align:center">This line will be centred.<br>
And so will this line.</p>
Let me know how you get on.