what WE would be useful for learning to me?

If I was to send in a CV and letter to get informal work placements (as in not structired internships) hoping to last around 3 months to the following places, 1)Is there a good chance if I show interest, and 2) How valuable would this be in terms of learning about trading/HFs/financial markets in general? Ultimately I want to trade, but I think any experience where I can learn about the markets could be interesting,

-try and work in research? (how relevant is this?)

-structuring? Doubt Im' nearly mathematical enough yet (standard is 1st year college economics major)

-risk management?

-offering to spend time doing anything on an IB's trading floor (I would guess
that this would not be a great learning ground due to
regulatory reasons not allowing me to do much)?

-offering to spend time at some random HFs (obviously I would have no chance at a big one)?

-what are these prop trading firms/arcades? would they offer any training to someone who's only going to be there for a few months (and maybe join after college)? Btw I'm in the UK, not the US - don't know if that makes a difference here...

I'm keen to do something that would really help me learn about this from gaining experience, rather than through reading (of which I have done a good bit), instead of getting something that will be useless but look good on a CV.

So thanks a lot for any advice.