Which route in to banking?

PLEASE HELP :) I'm 23 years old, have a BA(Hons) degree in International Business (with German), where I got a 2.1 grade (English grading system) and I really want to start a career in finance/banking. So what is the best route for me?

I have no background in finance (although at university I did study modules in Accounting, Emprical Research in Business, and a couple of modules in Economics, if that gives me any advantage?) and I have an A-level in Maths with statistics. I have some work experience from a four-month internship in business development and marketing (again, not sure if this would help) and spent six-months working in B2B telesales. Although I don't have a financial background I am very driven and eager to learn. However, there are so many fields within finance it's a bit overwhelming deciding exactly part of it will interest me the most!

I've seen gradaute job vacancies for an Analyst role in Corporate Banking or IB with BB so here are my questions:
1. Is it worth me applying for a graduate Analyst role or pointless, considering my background?
2. Will these grad roles only consider candidates who studied finance at university/ who did a finance internship?
3. If I have no chance getting in with BBs then where CAN I get in?

If I'm unlikely to be considered for any analyst role, which route in would you suggest? Many thanks.