Let's work through some things here:
I get a second hand understand that Hegel wasn't too keen on the idea of free will.
This is basically wrong. Or at least it's butchering things pretty badly on either the (a) understanding Hegel or (b) the meaning of free will.
First, let's skip that and mention some of the relevant literature.
Where [which (interpretation) of his works and which chapters] should I go to get a basic idea of his philosophy of free will or not?
The long place to go is Philosophy of Right which is an entire book about the nature of free will in Hegel's philosophy. There's some moderately readable commentaries written by Thom Brooks) and Dudley Knowles. Less readable but rather magnificent in scope is Modern Freedom by Adriaan Peperzak. Pelcynski is also pretty good.
The short place to go Hegel's encyclopedias. Conifold's answer (presumably) will point you to the right section.
Returning to the claim
Hegel wasn't too keen on the idea of free will.
Let's look at this from both potential problems. First, there's a huge question of what anyone means by a "free will." I think it'd be fair to say that Hegel isn't a big fan of the belief that you have a completely arbitrary will that can pick anything willy-nilly. Instead, he thinks the will makes rational choices, which is going to greatly limit its options. So far this is partially just a rehashing of the difference between randomness and free will.
Where there's potential to say Hegel is not a fan of free will is (I think) in three places. First, necessity has a big role in Hegel's philosophy. How exactly it works is a bit opaque, but Hegel's main mature project is the idea that spirit has been discovering its world and itself and its nature as free and rational, and that there are necessary steps in this (both necessary for its maturation and necessitated in history). So, the progress of history is arguably determined, but in Hegel's vocabulary it would still be "free" because these are the things that reason takes us to.
Second, rational choices occur within perspectival frameworks for Hegel. What you can perceive as possibly sensible is guided by your reason which occurs within a culture. (It is not at least on my reading arbitrary or unhinged relativism that makes this so for Hegel). This is why the book where Hegel works on this the most is called Philosophy of Right -- because what's going on is a two-fold process of discovery -- the will discovers it is free and then figures out how freedom plays out in the world, marching through ideas like possession, contract, crime, family, marriage, and society and the state. These structures limit what it is right for the will to do and thus what a rational will would do.
Finally, there's a big place where he's not a fan of free will: faith. Across a lot of texts, it becomes clear that he does not think you should choose to believe something that sets you apart from your society. Nor should you have independent values (See the note to section 105 of Philosophy of Right)
There's a lot more going on that makes his view dissimilar to a kind of Cartesian soul's free will or a Kantian moral self's. But to sum up, he thinks he's a fan of free will (in the free, rational will), but what he means by "free will" might not be compatible with what you mean.