Personally, I wouldn't even bother with any of those frameworks, as many of them are bloated pieces of shit, and are only going to confuse you. For example, instead of telling you to learn simple SQL queries, they'll tell you an SQL query should look like:
Code:
$db->select("id,name")->from("customers")->where("name = 'John'")->order_by("id")->limit(50);
Or some shit like that. Not sure what framework that is from, but it's from one of the popular ones. Why someone would decide that's a good idea is beyond me.
You're best off just writing your own framework from scratch. Can't find the one tutorial I really liked, but just Google writing your own simple MVC framework. Look into mod_rewrite, how it works, and start learning from there. It's honestly not that difficult, and definitely nowhere near as difficult as many of the "professional" tutorial writers make it out to be.
PS. While learning, make sure you're solving a problem. Don't just try to learn everything like you would history, for example. Pick a problem, and learn how to solve it. Then pick another problem, and learn how to solve that, and so on.