It's fine you don't get it, maybe you aren't the philosophical type - and A-Levels can be a bit scary when they widen the knowledge too fast. I remember this happening to me in Econ. To answer your question, Politics is pretty easy if you're good at essays and know a lot about the UK system already (makes learning and application sooo much easier). Even if you don't then you will learn how everything runs, and who's doing what as you follow the news. Here's what I did (AQA I think...?)
You start off Year 1 with democracy. What is it, where did it come from, what forms are there, which one do we use.
Then participation. Who participates in the UK politics, how, whats a pressure groups, whats scrutiny, what's XR and all that
The voting behaviour. Who voted for who in 2017 / 2019. What demographics vote what party and why. Media biases and such.
Then you move to voting systems. Which ones are there, what do we use, what others are used in the UK, what for etc.
The political parties. Which ones are there, what are their policies, where are they, what types of party exist. 1979 1997
Then you look at Parliament. What is Parliament, what do both houses do, how do they communicate. Legislative process and such
Finally the relations of the Executive, Legislative and Judicial. How they interact, what they do etc.
MEANWHILE: you study Liberalism, Conservatism and Socialism separately.
Year 2 is what I've just started and is comparative between US and UK politics. Can't tell you much about it yet. However you will study another ideology while doing this, but this is up to your teacher to decide.
Now you just decide if this appeals to you. I left out a lot of specifics - lots more work than this but this is the general topics. Keep in mind you've missed the first few lessons and might need to catch up.