How much do I need to know for a pre-internship?

Hey guys, I am an 18 y/o who will be starting my undergraduate studies in Econ at a target uni this month in London. I am getting around to searching for different 2017 Spring Week placements(pre-internship) and I was wondering how much I need to know about finance to be able to successfully land a spot in these pre-internships.

I've recently been doing some practice FX trading so I'm familiar with some of the Forex jargon but in other areas my knowledge is limited. Also, I was looking at the JPM site and they have seperate programs for 'Markets' - what is exactly is that? Any help would be appreciated!