I've done my BA and am currently doing my Masters in History at York, and have just accepted a funded PhD offer at Durham too - so I can say with confidence that York is a good choice!
As per preparing for an academic career, the above poster is right that it is a little early to know for definite if you will want to do a PhD. I wasn't sure until I finished my BA, and a lot of people take the MA year to really think it through before applying rather than applying for PhD right at the beginning of the MA. You're right that it's tough, as there is a degree of luck when it comes to going straight from one degree to the other without some kind of break - but recognising that and being open-minded about it is a good start. Although there is no real need to stress about your life almost 7 years down the line from right now, it will not hurt to have a long-term goal in mind - even if it's just that you want to be involved in something which uses your historical knowledge, rather than just the transferable skills (that was always my vague aim) - as it will encourage you to take up the opportunities on offer. Just don't force yourself into doing too much!
From my own experience at York and what's on offer there, there are some general tips I can give about how to make the most of your History degree, whether it is essential to your career or not: try to take a range of modules, and commit to them whilst keeping an open mind about what you might find interesting - I had gone into my BA convinced that I would love medieval history, but I'm now a fairly staunch early-modernist. Basically, try not to plan exactly what modules you're going to be doing because 1) in reality you may not get to do them, and 2) sometimes the best modules you take are the ones you just thought sounded interesting. Doing a language is a good idea; you'll get a free year of languages through the LFA programme, and having done Medieval Latin Level 1 & 2 I can recommend it, though you might not use it for research purposes until later on. There will also be a short course in reading medieval and early modern handwriting at some point (I think second year) which is another research skill worth picking up if you're serious about going on at least to an MA. Another thing worth doing is getting involved in writing outside of essays - this is a bit of a plug as I've been involved for a couple of years but there is a student magazine called 'The York Historian' which publishes student-written articles and is good CV fodder for academic and non-academic careers.
Anyway sorry for the long post, but hope this is useful!