The powerpoint material is the intellectual property of the lecturer and the university so will not be available as public access. Looking at the 1st year at Manchester there are two 60-credit units; PHAR11001 core concepts in semester 1 and then PHAR11002 Gastrointestinal system, liver and kidneys in semester 2.
If you are really keen to get ahead and you live near Manchester, you can go to the uni library and ask them what the core texts are for PHAR11001 and PHAR11002. They will be able to tell you. There will not be one core text but several e.g. one on biochemistry, almost certainly one on organic chemistry and cell biology. The uni library will have copies of these texts so grab a seat and have at it.
One heads-up is that Manchester uses the flipped classroom approach - very different from the lessons you have had in years 12 and 13. Here the lecture material/recordings of the lecture will be made available prior to the class with the expectation that students read the material/ complete the exercises in advance of the class. Then in the actual classroom, the lecturer will debate and discuss points from the lecture material and expect the audience to engage with the discussion. Thus, if you have not done the pre-work it can be embarrassing when the teacher asks you to comment on XYZ's model or the ABC case from chapter 3 and you don't have a Scooby