The phrase "well-regulated" is often confused to mean the modern term "regulate" as in government regulation. At the time it meant no such thing. What the phrase "well-regulated" meant was "well-trained," "in good working order," for example a well-regulated clock, or a well-regulated government, which is necessary for a functioning free society (this was mentioned in a speech given at a university in I think the late 1700s, I'll have to find it). Also, Alexander Hamilton in Federalist #29 talks about the militia and how, in his opinion, it really would be impossible for it to be able to have the characteristics of a well-regulated militia (i.e. a well-trained militia), because the militia, being the general body of citizens, could not all be trained up to that degree in proficiency with arms and war fighting.
The term militia itself is treated as a pre-existing entity in the Constitution, in Amendment 5, and also in Article I, Section 8, Clauses 15 and 16:
15: To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions;
16: To provide for organizing, arming, and disciplining, the Militia, and for governing such Part of them as may be employed in the Service of the United States, reserving to the States respectively, the Appointment of the Officers, and the Authority of training the Militia according to the discipline prescribed by Congress;
Note the usage of the phrase "the militia" as opposed to "a militia." It isn't saying Congress can form up a militia, it's saying the militia is pre-existing (the citizenry) and it can be called up by Congress.
Also the 5th Amendment:
No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a Grand Jury, except in cases arising in the land or naval forces, or in the Militia, when in actual service in time of War or public danger; nor shall any person be subject for the same offense to be twice put in jeopardy of life or limb; nor shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.
So the phrase, "A well-regulated militia..." doesn't mean a general body of citizens subjected to heavy regulation (in the modern sense) from the government." It meant a well-trained militia which could serve as both a replacement for a standing army, as historically standing armies had been used to oppress the people and thus the Founders didn't trust them, and also to serve as a check on the government itself.
Regarding the phrase "the people," everywhere the phrase "the people" is used throughout the Constitution, it is used in reference to an individual right.
It is a popular claim amongst the gun-control types to say that the individual right interpretation of the Second Amendment is a relatively recent creation, mostly by propaganda from groups like the NRA. This is nonsense. For one, we have the above points, but also, the concept of a fundamental right to self-defense, and hence arms, goes all the way back to the writings of Aristotle, Cicero, Machiavelli, John Locke, Thomas Paine, Charles Montisquieu, Sir William Blackstone (whose
Commentaries formed the core building block for the development of American law), and others. Fundamental right of self-defense goes back to the English common law as well (hence Blackstone writing about it).