How do I get good at reading literature?

The way I understand it is that analyzing literature and picking up on themes and symbolism is like building a muscle, there’s no secret short cut to it, you have you build it up over time. The two main ways I’ve found to build this muscle are

1). Reading as much as possible. Especially reading books that are influences to other books I enjoy so I can pick up on references and see the progression of literature as a whole

2). Reading analyses afterwards to get some insight into the deeper details that I missed along the way

I hadn’t really read anything since high school but within the past year got really into Cormac McCarthy and once I’m done with all of his books I’d like to branch out and see what else I can find. As much as I enjoy his works I can tell that a lot of stuff goes way over my head, and I feel like what goes over my head is more than likely the most important parts and why he wrote these books in the first place. I almost enjoy not understanding things all the way, it becomes something along the lines of a mystery for me to figure out.

Questions:

1). In addition to the two strategies I mentioned are there any other exercises I can do to understand the themes and pick up on symbolism better? I can usually get through the super descriptive abstractish parts somewhat easily but I had a lot of trouble with the dense philosophical themes in The Crossing and Blood Meridian and felt way out of my depth at some parts.

2). Should I try to avoid reading books that are “too complicated” for me and slowly wade deeper, or as long as I’m reading analyses along with it will I hopefully be building the muscle?

3). This one’s more of a general question that I don’t think there’s an objective answer for, but in your opinion what is the end goal with this type of reading? Should I always be trying to find how the points and themes of the book are relative to my life and proceed with those in mind, or at the end of the day is it more for entertainment?

4). My favorites I’ve read so far in order are Suttree, Blood Meridian and The Crossing. Any suggestions for what to read next once I’m done with McCarthy? Despite struggling with parts in those books the struggle is what keeps me interested