what/how do i get the textbooks required for my course?

For uni generally as a rule don't bother buying textbooks yourself. Your uni library will have everything you need and it's rare you'll need a specific textbook for a given course. Modules at UK unis generally aren't patterned around following a certain textbook and just suggest various different textbooks for reference and deeper reading after the lecture.
If you do need a specific textbook you will usually be told at the start of a particular module. In my experience I've never been required to buy a dedicated textbook except for a couple of specific language modules (and I've only been even recommended to buy a particular textbook for some other language modules!).
So save your money for now - if you need one you'll find out when you need it, and can save yourself a lot of money in the meantime by avoiding buying expensive textbooks you may only use once!

Thank you so much!! this is super helpful!! but i like to use/mark on textbooks, practice different problems & im also aiming for a first class degree and incase i would need extra references, do you think its a good idea if i contact my lecturer?

There will be plenty of textbooks available in the library with different practice exercises etc. Note also most textbooks don't have an answer key (these are usually separate books and may not be purchasable by/made available to non-instructors in some cases).
You can get 1st class marks without buying the textbook. I've managed to do so in modules I didn't buy any textbooks for and just used library and (even more frequently) digital resources.

Hi @astr0star123
That’s not a silly question at all—starting uni can feel like a big jump, and it’s totally normal to have questions like this!
As someone mentioned above, you usually don’t need to buy textbooks upfront. In fact, buying all of them can get very expensive, and most students rely on the university library instead. At both the unis I’ve attended (for undergrad and postgrad), the library had all the key textbooks available to borrow—typically for 30 days, with auto-renewals unless someone else requests the book (but this process will vary at each uni).
Many books are also available to read online through your uni library account. If you prefer hard copies, you can often print individual chapters too.
Once you're fully enrolled, you’ll get access to a system like Canvas or Moodle, where each of your modules will list any required or recommended reading. That’s usually the best place to check what you actually need.
Hope that helps, and best of luck getting started at uni! 😊
Megan (LJMU Rep)