Hi,
I'm a web developer and have been developing professionally for two years. What is important, based on my experience is understanding what is happening, under the hood. Which is to say, you need to understand programming first, then choose a framework to work with.
Don't debate about frameworks or systems to work with as of right now, rather, concentrate more on understanding design patterns and programming. I would recommend you try learn HTML, CSS, PHP and Javascript to get a firm grip of what they are capable of. It will be useful later on when you compare frameworks and choose one to focus on.
Joomla does have a bad name, but it's an awesome framework - when it is in the right hands. One huge drawback of these frameworks is that they tend to lose sight of the goal and you end up battling with their tiny nitty gritties in terms of language, conventions, etc and it will basically be shooting in the dark. With a solid understanding of core concepts, you can get all this stuff much, much faster.
When all is said and done, ditch Joomla and head over to
http://drupal.org! *shameless self promotion* then you follow me on twitter @therealchiko , would be happy to share what I can.
