i've seen some ridiculous virtue signaling recommendations on hn before but this takes the cake. have you actually read the book? wigderson is an IAS professor (for those that don't know, einstein and godel were IAS professors) and this book is a research survey (most of the theorems have refs to papers). i've read both sipser and hopcroft ullman and i'm still pretty far away from being able to easily read it. and you're recommending this to someone that learned js from a bootcamp. you think maybe she's not the target audience?
so that i'm not labeled as just a critic: the standard formal languages book is sipser
https://www.amazon.com/Introduction-Theory-Computation-Micha...
it's colloquial and has a lot of diagrams and "intuition". people really like it but i actually think hopcruft ullman is better because it's more structured
https://www.amazon.com/Introduction-Automata-Theory-Language...
The question then is "what next?" To which I would say that you want roughly the equivalent of a course titled something like "Introduction to Computation" or "Automata Theory & Computation" or whatever. That is, you'll want to understand things like Universal Turing Machines, Finite-State Automata, Formal Grammars, and some basics of Computational Complexity Theory (the same "Big O" stuff you'll hear mentioned in the Data Structures & Algorithms class, but going a little bit deeper). This stuff isn't necessarily required to do a lot of "grunt work" programming, but it starts coming into play if you want to do some more advanced stuff.
One of the classic texts in this area is by Hopcroft & Ullman.
https://www.amazon.com/Introduction-Automata-Theory-Language...
And on a semi-related note, there's a really good course on Youtube: MIT 6.042J Mathematics for Computer Science, taught by Tom Leighton[1], that you might find useful as well. A version of the book[2] used in that course is freely available online as well
https://www.youtube.com/playlist?list=PLB7540DEDD482705B
[1]: https://en.wikipedia.org/wiki/F._Thomson_Leighton
[2]: https://people.csail.mit.edu/meyer/mcs.pdf