a) What is the political spectrum?

A political spectrum is a structure for describing and comparing various ideologies, viewpoints, and parties according to their views on issues and programs. Generally speaking, it falls into two camps: left-wing (liberal or progressive) and right-wing (conservative or traditional), with views like authoritarian, libertarian, and centrist falling somewhere in between.

b) What is the difference between left and right wing politics?

The left wing is more liberal and the right wing is more conservative. Liberals focuses more on combating climate change while supporting more active government involvement in addressing social and economic issues. They also involve in progressive social policies, business restrictions, and universal healthcare. Conservatives often want less government involvement, placing a strong emphasis on personal accountability, free-market ideas, conventional social values, reduced taxation, and school choice programs.
c) What is the difference between authoritarian and libertarian governments?

Authoritarian: Concentrated authority, frequently held by a select few or a single leader. substantial authority over societal, political, and financial facets of existence.
Libertarians: Support little involvement by the government. Decentralized power, emphasizing personal liberty and self-determination.

d) Where does the government of Ingsoc and Big Brother fit along the political quadrant scale?

I would say ingsoc and big brother fits along the top right quadrant