For metapolitics, if you just want a general introduction, I would look for articles on dissident websites. My understanding of it is that it is the political maneuvering/manipulating/persuading of society through non-political (overtly) means.

For example

https://counter-currents.com/2012/12/metapolitics-and-occult-warfare-part-1/

As Evola describes it, occult warfare is essentially identical to metapolitics.

Metapolitics deals with the underlying causes and conditions of political change. Metapolitics operates on two levels: intellectual and organizational. Metapolitical ideas include moral systems, religions, collective identities (tribal, national, racial), and assumptions about what is politically possible. Metapolitical organizations propagate metapolitical ideas, bridging the gap between theory and practice. Examples of metapolitical movements include the European New Right and North American New Right.

Small metapolitical changes can lead to vast political transformations over time. For instance, the values articulated in the Sermon on the Mount eventually overthrew the whole ancient world. But since metapolitical causes are often remote from political effects, and since metapolitical causes are often abstract and esoteric ideas entertained by only a few, metapolitics is invisible to most people, who focus only on the concrete and immediate. Metapolitics is, therefore, “occult” in the literal sense of the word, i.e., “hidden.” But it is often hidden in plain view and need take no special precautions to conceal itself from the public eye.

Another, see the comments as well

https://counter-currents.com/2010/11/on-metapolitics/

Dr. Johnson's book, Truth, Justice, and a Nice White Country also has a good introductory section on metapolitics

POLITICS & METAPOLITICS

In “Propaganda and Organization,” Hitler deals with the relationship of metapolitics to politics, for propaganda refers to communicating the intellectual preconditions of political action, and organization refers to creating the institutional framework of political action—two essentially metapolitical activities.

Hitler begins by emphasizing the priority of metapolitics over politics: “Propaganda had to run far in advance of organization and provide it with human material to be worked upon”47 (Mannheim trans., p. 578). Hitler explains that, “I devoted myself to propaganda in the first period of my activity in the movement” in order to “gradually fill a small nucleus of men with the new doctrine, and so prepare the material which could later furnish the first elements of an organization” (p. 581). One cannot create a political organization out of men who are not of one mind about who they are, what they are doing, and why.

Hitler declares himself “an enemy of too rapid and too pedantic organizing” (p. 578). Organizations necessarily congeal into hierarchies, and the people at the top naturally resist challenges from below. It is crucial to avoid premature organizing, and rigid (pedantisch) structures, lest inferior people be placed in positions of responsibility and prevent superior people from rising to replace them. Thus, “It is more expedient for a time to disseminate an idea by propaganda from a central point and then carefully examine the gradually gathering material for leading minds” (pp. 579–80).

Hitler also cautions against using superficial criteria for judging the individuals drawn in by propaganda efforts: “Sometimes it will turn out that men inconspicuous in themselves must nevertheless be regarded as born leaders” (p. 580). Hitler’s aim in the early years of the National Socialist movement was to create a vanguard, an elite that would lead the National Socialist German Workers Party and eventually all of Germany. To create that elite, he needed to attract like-minded people and convert others to his way of thinking by articulating and disseminating his worldview, i.e., through propaganda. Once these outreach efforts bore fruit, the party had to recruit people with leadership potential, then train them to ever higher levels of awareness and competence.

https://www.theoccidentalobserver.net/2018/10/17/the-white-nationalist-manifesto-by-dr-greg-johnson/

A manifesto is a declaration of policy, beliefs and aims, motives and intentions, making them clear and obvious, or manifest, with nothing hidden or held back. In the introduction Dr. Johnson describes the book as “an essay in metapolitics….to offer a clear, concise and persuasive synthesis of arguments that I have been developing for more than a decade” (p. 7), with metapolitics defined as “creating the conditions necessary for political success” (p. 6).

Arktos also has some articles on metapolitics as well, fairly long.

https://arktos.com/2018/10/22/metapolitics-and-the-right-part-1/

https://arktos.com/2018/10/23/metapolitics-and-the-right-part-2/