Ok, I have MLF installed - I like the format a lot. I installed another theme I like as well. However...

I have no idea how to edit a site such as this, aside from the CSS. I understand the particular format relates to a template engine called Smarty - I am not experienced with, or familiar with this. I know how to edit HTML well, and PHP decently - I don't know how to even approach editing this code, though!

To use a hard example, say

I wanted to change something simple like change 'New topic' to 'Post topic' or wanted to change # of allowable characters in a form field. Where to even look? How to approach? Can the HTML be edited?

Any direction or guidance much appreciated, thank you!