Best place to do work experience?

Doesn't really matter honestly. The only use of it is so when you apply for your first job you can say you did do some work experience somewhere and maybe can demonstrate you learned something from it.
A retail, customer service or food services oriented job (such as your cafe suggestion) is probably a good bet as you can say you have experience of e.g. managing a till, handling cash, working independently in a team in a busy environment, and maybe some specific things (e.g. how to use an espresso machine or something).
6th forms won't care where you did your year 10 work experience and universities most certainly won't (and you absolutely should not be wasting personal statement space talking about it!).

Doesn't really matter honestly. The only use of it is so when you apply for your first job you can say you did do some work experience somewhere and maybe can demonstrate you learned something from it.
A retail, customer service or food services oriented job (such as your cafe suggestion) is probably a good bet as you can say you have experience of e.g. managing a till, handling cash, working independently in a team in a busy environment, and maybe some specific things (e.g. how to use an espresso machine or something).
6th forms won't care where you did your year 10 work experience and universities most certainly won't (and you absolutely should not be wasting personal statement space talking about it!).

Pretty much this, most work exp is worthwhile just to get that first few weeks/months in to have a line on the CV and get used to how employment works and the responsibilities, even if it's just turning up on time and interacting professionally. There's not many employers like taking on totally new workers because of the time and effort it can take, so getting that first exp (and a reference if you're lucky) somewhere is always valuable imo. Ditto unis won't really care about this and it's not worth a personal statement mention unless it really ties into what you want study.