Panadol is a company name for paracetamol – a small molecule that helps you deal with pain.
It’s not very acidic (I like your word “acidy”). In the structure of paracetamol there’s a ring of 6 carbon atoms. Hanging off that is an oxygen and attached to that is a hydrogen atom. Turns out that it’s fairly easy for the hydrogen to fall off, leaving its electrons behind. That produced H+, which is what acid is. So it can produce a bit of acid, but not a lot. It’s not a strong acid like the hydrochloric acid in your stomach.
Panadol, like other medicines, also contains a bunch of other stuff that’s not paracetamol, but which is there to make your body better able to absorb the drug. It’s called the “formulation”. People who study pharmacy know all about that.
Paracetamol is the ‘active ingredient’, the bit that has an effect on your body. Paracetamol reduces pain and fever by acting on molecules called prostaglandins, which make you feel pain.
There’s 500 milligrams (half of a gram) of paracetamol in each tablet. That amount is very tiny, so to make up a tablet that is big enough for you to take, the rest has to be an inactive (doesn’t affect your body) filler. I think that some sort of sugar is usually what is used. So why doesn’t the tablet taste delicious? The paracetamol has a bitter flavour that you probably start to taste if you don’t swallow it quickly.