How to proceed further?

Hi everyone.So this is my first question on this site.

I have received an offer for undergraduation in MA(hons) economics at University of Edinburgh and will be beginning first year in September this year. I would like to add that I am an international student. I am really very interested in investment banking and I will be aiming for a FO job throughout my university. I have done my research and though I have got a basic idea, I am still quite confused.

I will be really thankful if someone can just explain to me how should I proceed from here for the next four years of my university. Like what all should I prepare for beforehand during my current vacation as (I am free at the moment ) before university or when I start school in September what all applications should I be making( as in for spring weeks or internships) or what all networking should I be doing and so on.

I know it is quite a lengthy question but I am really confused and need some direction on the path I should take ahead.Any comments or help is appreciated. Thanks in advance.