Having traveled that road, here are my thoughts.
Reading comprehension, clear writing, and analytical skills are paramount. You don’t have to be any good at math. Most lawyers aren’t (see, e.g., this).
To get into law school, you have to make good grades in college, and get a high score on the law school admission test. Not everybody can do that. The LSAT is a lot like an IQ test, and high-IQ societies accept LSAT scores as proxies for IQ scores. Getting into law school is competitive, and all law students are above average in intelligence.
Law study is hard work. Law school is 3 years of grind. It’s not fun. There’s a lot of reading. On law school exams, you’re given a set of facts, have to identify the legal issues, know something about the legal rules that apply, and reason logically from the facts through the applicable law to a conclusion. There’s generally no “right” or “wrong” answer, but you must know the material — you can’t b.s. as much as you did in your undergraduate courses — and you’re expected to be able to argue either side of a given case.
The bar exam is stressful. I can’t say more about it than that, because it has changed over the years, and I don’t know what it’s like now. Mine was 3 days of 8 hours a day, 24 hours total, in 1-hour blocks. Except for a multiple-choice section on legal ethics, it was all essay-type questions.
The job market for new lawyers is, and always has been, challenging. People pursuing law as a second career will likely fare better at landing good jobs, because many law practices require specialized knowledge outside of law. For example, if you go into banking law, it helps to have been a banker for a while. Law can be an excellent career advancement for people in engineering, medical fields, business and finance, etc., if they have good communication skills.
Most lawyers spend little or no time in courtrooms. It tends to be a desk job. Lawyers are information processers. You do legal research, possibly interview clients and witnesses, devise legal strategies, produce briefs and memoranda, and do oral presentations in client conferences, negotiations with opposing lawyers, and/or to judges, arbitrators, or mediators. You may talk to experts, read technical reports, write a detailed factual summary, and then explain what it all means to a judge with no knowledge of the subject matter.
There are easier ways to make a living, and most lawyers don’t get rich. Legal careers are characterized by heavy workloads, long hours, strict deadlines, and vast amounts of paperwork. In addition to legal knowledge and skills, lawyers need people skills and the ability to work under pressure. Often the hardest part of a lawyer’s job is dealing with clients. People with legal problems typically are under a lot of stress. As for the intellectual demands of the work, legal problems vary in complexity from complicated to extremely complex, and may require a very high level of abstract thinking.