Congratulations on your offer! I am a civil engineering student at Bath. Each course will differ from uni to uni but i can give you a bit of insight into mine.
You'll most likely have a mixture of lectures and tutorials to start. Lectures are where you can listen to your lecturer teach about your module which for myself has involved geology, the built environment, mathematics, physics behind structures etc. Civil engineering is very broad so you'll learn everything from geography, to transport to building and bridges etc. Tutorials are opportunities for questions, you may be doing practise questions from old papers or going through tutorials with your lecturer. These are more for you to practise an gain an understanding of how your knowledge is put to use.
You'll have a mix of both coursework and exams. For myself i have had a number of group projects which involve designing structures around the brief given, designing foundations, performing calculations within the structure and the outside environment and presenting findings in multiple forms such as reports, essays or posters. In addition, there will be exams at the end of each semester. The layout of these will differ uni to uni and module to module. I have had some multiple choice, some essay structure etc. They will most likely be open book as civil engineering focuses more into application than facts which may also mean theyre online but again this is totally dependent and may be different for you.
You should be prepared to be independent. This goes for any course - no one will be checking up on your progress (excepting times set to have discussions with your tutors). You need to reach out with any questions or help you may need. They recommend to treat university like a 9-5 and put in the samr amount of independent study as you are there in person. I.e,., If you have a 2 hour lecture then put in 2 hours of independent work. When you do this is totally up to you, You dont actually have to work 9-5 if working 12-8 works better. or if you want to spread it out even further - thats the benefit, you can totally organise your own schedule around your free time.
Hope this gave a little insight ! Feel free to respond with any more questions about the course - Sophie (uni of Bath)