Your first choice is law and I am a lawyer, so, here are my thoughts:
In the 19th century, people learned the law primarily through self-study and apprenticeship, so I'm tempted to say start with Blackstone like Lincoln did. But that probably isn't very good advice.
Legal education in the US in the 20th century came to be premised on what is known as the "case method," ie., you read published opinions from actual courts deciding actual controversies. You might see potential here for a self-study method, but there are some caveats:
First, it's widely believed that you should only read cases in the context (at least in the first year) of a course where you are subjected to a "Socratic" pedagogy that is designed to force 22 year olds to learn how to argue positions based on the law as it's actually articulated in the cases they are reading instead of what they think the law should or might be.
Second, there are a lot of cases, they are published chronologically and not organized in any coherent way, and the content of the opinions is often taken up with procedural details with the potential to distract a novice. So there are "case books," which are collections of abridged cases organized topically with additional explanatory material and intended for use in a "Socratic" class context. See, e.g., https://www.amazon.com/Torts-Introduction-Law-Richard-Epstein/dp/0735500479. I don't recommend this as a method for self-study.
The alternative to the case method would be what are referred to as "treatises," which are what they sound like. A classic of this genre would be. https://www.amazon.com/Prosser-Keeton-Torts-William-Lloyd/dp/0314748806 Frankly, this would probably be a better way to start a self-study program.
However, I would hope that you would start looking at actual cases eventually. An alternative and perhaps better approach to studying cases than the "case books" discussed above, which might work for self study, would be to look and see if your state has a body of "annotated" statutory law. There is a lot of variety here, but the states have, with varying degrees of success, attempted to codify their common law in statutes, and they usually then publish these statutes with annotations citing to cases that interpret or rely on the statute. Due to a recent US SCt opinion, for example, Georgia's annotated code is now available for free download at: https://public.resource.org. It would probably be best to have some grounding via treatise first, though.
The curriculum looks something like this:
Contracts. The first year course teaches you the law of obligations and some stuff about remedies, advanced courses teach the details of the Uniform Commercial Code, and more about remedies.
Torts. This is the law of how you get civil damages (or potentially some other remedy) to make you whole when you've been injured by the negligence or intentional wrongs of another.
Property. This is a class about property rights that is often an excuse to teach the history of the common law system as much as it is about tenancy.
Constitutional Law is generally divided into a semester about the boring parts of the constitution and a semester about what my professor called the "Jerry Springer" parts of the constitution.
Civil Procedure teaches you about the Federal Rules of Civil Procedure, which is the model for the state civil procedure codes (but sometimes diverges considerably). Advanced topics include Federal Courts, which is a more specific look at federal topics in this area, and potentially a state specific course. This if very important. Much of what you will read in a published opinion is about this stuff and not about the substance of the law in dispute.
Criminal Law is an introduction to how the criminal justice system thinks about crime; the guts of criminal practice are actually constitutional law subjects that are covered later in a course called Criminal Procedure.
If you want specific advice about what to read with respect to a specific subject matter or jurisdiction, let me know and I'll try to help. If you are mainly interested in a higher level understanding of law as a philosophical subject, well, I'm not the person to speak to that.