Just use plain html.
To add a line break (between events for example) ad an <hr> tag.
Please use the <strong> tag for making bold rather than <b>. It's better semantic markup. 😜
Copy an existing page and replace all the content apart from the bit that says:
---
layout: default
title: Tidal Club
---
The navigation doesn't update dynamically when you create a new page, so you need to edit _layouts/default.html.
Do this by copying an existing menu item such as:
<li><a href="sheffield.html">Sheffield</a></li>
NB: You need to do this in two places so the mobile menu also updates.