Pharmacy work experience

I would like to do work experience in pharmacy but I’m not too sure for how long I should do so, any suggestions?

you don't need an experience and you can find some online if you can't get irl xx

You can ask at local Pharmacies but, as above, you do not need w/exp for a Pharmacy degree.
You need an awareness of what the job is -
Community pharmacist job profile | Prospects.ac.uk
Hospital pharmacist job profile | Prospects.ac.uk
and an awareness of the NHS Core Values -
The NHS values | Health Careers
Any customer service experience such as retail, hospitality, charity shop etc is useful for answering 'how would you handle a difficult person/situation' interview questions.