I want to know about like all basic terms like I am even unaware of what does left wing and right wing mean.
What is conservative, libertarian, anarchist, fascist and terms like that?
Also the thing like economy as in politics, economy is also discussed so I want to know about that too like how each isms like capitalism, communism, socialism, and etc. wants to run economy.
And some basic stuff.
I am 18 and I think I should be aware of this.

Having the desire for this understanding is wonderful! It shows you are truly curious about the world you live in, and the things that affect your life and those of your neighbors near and far. Understand that some of the terms you used aren't universal around the world. Many nations political systems use the same terms, but they have slightly or drastically different meanings, so for the context of your goal, its probably helpful to start with understanding the politics of the nation you live in.

First, what is politics? Politics comes from the word "policy". As in, politics is the system we use to decide what policies or rules a nation follows. That's really the root of it. All the complication comes because various people and groups don't agree on what policies should be put in place. The problem is that there is not one set of rules that everyone agrees works (or can work forever).

For a beginning understanding I'd probably point you a civics or government textbook. There will likely a chunk of the nations history mixed in because so much of politics is derived from what was tried before, what worked, what didn't, and what was tried next, and the cycle repeats with different follow-on attempts.

For my country, thing is the history that i listened to in my classroom about my country Pakistan is kinda biased. We have huge hold of military in our country and censorship is common so i fear i may not find a good source to get unbiased grasp of politics in my country. There was an autobiography of a president that I read and that is the only political thing I knew off. But thank you for educating me what politics even mean in first place.

A great starting point is your nation's Constitution. It is a present point in time. It exists today as the supreme set of policies the nation follows. From there you can look back in history as to how and why that contents of the Constitution came to be. You can also look forward to those that are trying to make changes to the policies in the Constitution. Each will give you a greater understanding and are equally important.

I downloaded the Constitution of Pakistan to take a look at it, and its 222 pages of mostly dry reading containing not only the resulting policies but also the processes of your government. For someone just beginning its probably too much to start with, but I found this site that gives a basic walkthrough of the different parts of the Constitution of Pakistan with some more approachable explanations. So perhaps start here.

We have huge hold of military in our country and censorship is common so i fear i may not find a good source to get unbiased grasp of politics in my country.

Everything written by humans contain some amount of bias. This is especially with politics. You will likely not find any completely unbiased sources (except the Constitution itself). However, this is where the looking back in history helps. You can start to see the patterns of how things came to be. As an example, looking at a meal of a complicated dish may be impossible to figure out what it looked like at the beginning, but if you see the raw ingredients when it is being cooked, you can gain a greater understanding of the final dish.

Start forming questions about what particular aspects of life in your country or polities you're interested in learning about, and let that guide you to more specifics answers.

can i do this when learning about other countries' politics like US, UK, Middle East and etc.?