Frameworks tend to be pretty advanced code. I would not suggest trying to learn PHP from a framework.
The best way to learn PHP is to read scripts where you can see ALL the input and ALL the output. Frameworks tend to use a lot of includes, which means you can't see all the input (as easily), and they do not have a fixed output that you can look at.
I learned PHP the way you are, with no prior programming experience. When I reached the advanced level, however, I discovered that there were gaps in my knowledge: basic PHP principles and syntax that I had never seen or heard of.
That's why, like laserlight said, a book is a good idea, but you can also find a wealth of tutorials in the internet. Try PHP for the Absolute Beginner so that you have a good grounding, and you don't have gaps in your knowledge like I did.