I would highly recommend you start with this book first https://interpreterbook.com https://interpreterbook.com and then feel free to read Nystrom's online book

I would highly recommend you start with this book first https://interpreterbook.com https://interpreterbook.com and then feel free to read Nystrom's online book as ablerman suggested. The you can read more formal CS book for the sake of covering the necessary theory. Another suggestion would be to check the source code of various SQL databases, such as SQLite3 and PostgreSQL. Also, I would suggest to read lots of lots of source code from github. Here is a short list of suggestions: * https://github.com/lemon-lang/lemon * https://github.com/d5/tengo * https://github.com/wren-lang/wren (by Robert Nystrom) * https://github.com/tj/luna (by TJ Holowaychuk, creator of Express.js)