The constitution contains the "Bill of Rights." The first 8 amendments detail rights of an individual. If other rights exist beyond those enumerated in the constitution, where are they documented, and how would a non-lawyer know about them?
Yes, there are other rights.
First of all, there's the 9th Amendment, which contemplates that unenumerated rights exist:
The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.
The courts have used this to find other rights, such as the right to privacy (which led to a right to an abortion.) The courts have also interpreted some enumerated rights as giving other rights, such as the right to have an attorney provided for you if you can't afford one.
As a commenter mentioned, state constitutions will sometimes include rights not specifically stated in the federal Constitution. For example, the Wisconsin constitution says
The people have the right to fish, hunt, trap, and take game subject only to reasonable restrictions as prescribed by law
which is not in the federal Constitution.
Rights may also be given by laws. For example, here's part of a Wisconsin law I picked at random (emphasis mine):
If it is shown that there is probable cause to believe the allegations under sub. (1), the court may release the subject individual pending the full hearing and the individual has the right to receive treatment services, on a voluntary basis, from the county department under s. 51.42 or 51.437, or from the department.
The Constitution of Massachusetts begins with an enumeration of rights in "Part the first". They include the right to seek safety and happiness, the right to freedom of religion, the right to form a government, and to totally change the said government.
Other state constitutions can be consulted, many have similar sections, although the explicit right to revolution is exceptional.
The document is published and can be read by anyone. There is no requirement to be a lawyer to access the text of any law.