I don't do languages so I can't comment on your course. Sorry.
The area around the university and Cottingham (where some of the halls of residence are) are fairly safe so you don't need to worry. There are obviously some more run down areas of Hull but as a student you shouldn't have any reason to go there.
For first year, I'd recommend going into Halls. The Lawns in Cottingham is where most students go, there is about £100 a week but this includes all your evening meals and obviously bills/internet so is actually quite good value for money. That works out at about £3500 a year. They are also currently building some new accommodation on campus which will be ready for people starting next year, this is going to be really luxurious, all en suite, double beds ect. so that will be more expensive.
In terms of student housing for your later years, I'd say with bills they are usually around £80 per week and without bills £65/£70 per week. These obviously don't include meals like the Halls do and usually have longer contracts so actually come out more expensive than the Lawns. However this is still much cheaper than at most other Universities as Hull has really low living costs, both in food and house prices.