Ask a current history student!

You're in luck. I'm a joint honours student with Criminal Justice. If you did it with French, of course you have greater international opportunities if you were interested in working abroad. What I've found from my course, and talking with lecturers, is that a lot of students of history go to work for the government as a civil service. Personally, I'm applying for the Civil Service Fast Stream soon in hope that I could go into that after graduation. Give it a look, there's opportunities in the foreign office. https://www.gov.uk/faststream

Reading recommendations? A difficult one. I'd say read what interests you if you already know what you want to do your dissertation on. If you're joint honours, you may not have to do a dissertation, or it may be optional.
However, reading is specific to a module, and further to that, specific to your essay(s) and assessment focus. You probably won't know what classes are available to you until you start. Then, you'll be provided with a reading list for all modules. Before I started, I contacted my school's administrator for a reading list. She provided me with useful books for each module. Like I said it was useful, but I'd hold back to see what your course tutor recommends, and what your library has to offer. Unfortunately my focus is on the 20th century so I can't recommend any 'generalist' authors to give you an overview. Perhaps posting in history asking for a historian who writes about your specific interests?

How do you become excellent at history? I think you have to be interested in it, firstly. You have to be interested in what you are discussing (in an essay), know other historians point of view, assess the importance of events, and most importantly, create your own opinion and argument. I guess you become skilled by knowing what is wanted of you and constantly practising.

I revise by collating all the information I have on the topic I'm revising. I then read (online, journals, academic sources) for additional information which may help me. I make sure to have historiography (contextual historians opinions) to add to my argument. Then I type up notes, highlight, and if I have time I rewrite onto revision cards and highlight again.

To create a clear structure I recommend typing up an essay plan and adding to it as you go along. Make sure you write down every thought you have- you don't have to include it in your essay. I spend a few weeks writing a detailed plan, editing the structure and moving things about. Read, read, read!

I wouldn't say I'm naturally skilled in liberal arts but I find 'the arts' way easier than the sciences. I think you can always improve your ability regardless of subject by understanding what is expected of you.

If you're looking to improve your analytical ability I'd recommend finding relevant quotations to your essay question (for example), and questioning whether anything contextual, or a historian's opinion contradicts it. You need to constantly be questioning what historians are saying.