A Level English Literature vs IB English Literature HL?

I think for the A Level, you learn fewer texts, most or all of which have been originally written in English. In HL IB you have a chance to do a wider range of texts, including texts that have been translated from other languages. I think you study more texts in IB. In the IB there is also an aural assessment. It would probably be a good idea to look up both syllabuses online and contact your teachers or find your school/s prospectus or website to see if you can find out which exactly texts you are studying.
I wish I could tell you more, but I don't do either- I just know lots of people who have done English Literature A Level/IB (I do English Literature Pre-U).

And how does English Literature Pre-U differ from the rest?

The Pre-U syllabus is supposed to be something like a bridge between school and university, so it is slightly harder than A Level. It's the same level of qualification (sixth form), but the grading system is different. The highest grade is D1, which is more than an A*, the other grades are roughly similar to A Level grades. It's a linear course taken over 2 years, so there's no AS.

I think the difference between Pre-U and A Level isn't particularly big for English, in comparison to the IB course.

In Pre-U you study 4 texts for the exam (2 plays, 1 set of poems, 1 novel), have an unseen paper and do coursework. The coursework in known as a Personal Investigation and you get to decide the question, texts and theme- although you will probably study texts for the coursework in class and add some of your own. So I think there's more freedom in terms of the coursework. I think you also study more about different periods of literature due to the fact the unseens cover a large period of time.

Are you studying for a qualification independently? Or are you studying it at a school?

I just ended my penultimate secondary education year and entering my finial one,so I'm contemplating on my tertiary education choices.
Undecided whether to do the IB or A-Levels. Unfortunately,Pre-U schools are even further out where I live or exclusive to independent schools.
What made you choose Pre-U(s) over the aforementioned courses.

I liked the fact I could learn about different periods of literary history in the Pre-U as well as the freedom of the personal investigation, but to be honest, the real reason I took Pre-U is because the sixth form I got into doesn't do the A Level for English as they do the Pre-U instead.