Pure economics or Economics and finance?Watch
Also I'm sorry if someone has asked this question before I did look but couldn't see it.
That said, applying for pure Econ is probably a good idea since you have some flexibility in units and usually you can still switch Econ courses at the start of your second year.
Courses in Finance don't necessarily help you practically, but they give you a good introduction to financial concepts like CAPM, APT, EMH, valuations, derivatives, corporate finance, etc.
But this is from 2nd year onwards. Don't worry about it too much now, in first year all the modules of the different economics courses are exactly the same (they were at my uni anyway) - once you've been at uni for a bit and get to know about the modules taught you can request to change to a different type of economics (we were allowed to do this upto the first few weeks of second year)
The thing that put me off a lot of Economics and Finance courses was the fact you had to study accounting modules, whereas on pure Economics degrees you can take the financial modules which are more interesting and avoid any accounting modules. (For example, I'm doing a pure Economics degree, but I can take modules in Portfolio Theory, International Banking, Options and Futures, Economic Finance, Empirical Finance, etc.)
I feel the advantage of learning about finance is being under-represented here. Yes, there are less optional modules and flexibility if you take an Econ and Finance degree, but having taken Finance and Accounting modules will help significantly for the analysis of securities if you work in the finance sector in the future. In fact, quite a few Economics models learned in courses is not very practical or applicable in jobs, but doing more finance/accounting can help you pave the way in qualifying for the CFA. Nevertheless you need to consider where your interests truly lie or are you just doing it to get into a career which I do not recommend.