I actually wouldn't recommend oUF_Simple as a starting point for anyone new to programming. It's great for people with a programming background who are new to Lua and/or WoW addons, but I think it's really way too big and complicated for someone without any programming experience.
Instead, I'd recommend looking at
oUF_Classic or
oUF_Lily, the two example layouts Haste (the author of oUF) links to on the oUF page. Both are pretty simple, with the main parts contained in just one file, and provide much better starting points for (a) understanding how oUF layouts work, and (b) building your own layout.