How to self-learn law today, like those lawyers in the past who never went to law school?

Question

One can simply read law textbooks and judgements of legal cases, but what else?

Answer 1

If you simply want to acquire knowledge in law, reading is the most effective way.

Even law courses (at least where I am from) consists of tons and tons of reading. Read, read, read. Usually the items are:

1. Legislation (i.e. the actual law). If you are attending an Intellectual Property class, you will be assigned to read Copyright laws. In a Criminal Law class you will read the laws about prosecution, and legal definitions of various crimes.
2. Textbook / lecture slides. They will provide a laymen explanation of the concepts and terms you come across in the legislation, along with simple examples.
3. Legal cases. These are especially important in a country where Common Law is in practice.

Here is a fact: you cannot learn every aspect of law. There is simply too much. That is why there are lawyers who specialize in contract, accident compensation, land dispute, etc.

Answer 2

In the states of California, Maine, Vermont, Virginia, and Washington, an applicant who has not attended law school may take the bar exam after reading law under a judge or practicing attorney for an extended period of time.
In 2013, 60 people became lawyers this way out of 84,000 via law schools.

from Wikipedia®