It is fine to use the quickstart. Take a look at the template manager settings and enable the cache in there. Make sure development mode is not set and then try again.
There are so many things that could be slowing down your site that it is impossible to say. Are yo using modules that require external data to be loaded? That is often the most common cause. Twitter, Facebook and Video feeds are a prime example of this. I recently removed a weather module from my site due to this very problem.
Please pos a linkt to your site so we can all comment on its speed.
