You will be learning how to write at a university level in first year. This takes time to get the hang of and you will gradually become aware of what standard and style is expected by each of your lecturers. You will discover how an English essay is different to an Anthropology essay, for example.
You will receive guidance about writing during lectures and tutorials and you can always contact tutors and lecturers with any questions you have. The feedback you get on assessment tasks early in semester is also a good guide. The department in which your subject is taught may have an essay-writing guide for first-year students. Ask your tutor about this.
Due to time constraints, your lecturer or tutor is not able to read through draft essays and provide feedback. An academic adviser at Academic Skills can do this. This service is free to all students and you can see an academic adviser up to four times per semester. They can help you analyse an essay question or work out an assignment plan. They can give you feedback on your first draft, help you to develop your argument and improve your academic writing style.
If you are disappointed with your marks, keep in mind that most students get lower marks in their first year at university than they got in Year 12. You are being measured against people who have done well at school and gone on to further study. This means that you can get worse marks without doing worse work.
Also, people take time to get their heads around new skills and University is different to school. You need to do your best to figure out how it is different and your tutors and academic advisors can help. You will have all year to develop these skills as prospective employers and academics will look at marks only if that is important to their selection process. It is the later year marks that normally count in their decisions. This does not mean you can afford to waste your first year! It means that you can use it to learn how to do as well as possible next year.