There are basically no restrictions on self-taught majors. When choosing a major, you can refer to the examination plan columns of local self-taught provinces and cities and choose a major that suits you. You can also go to the university continuing education center for consultation.
In principle, there is no time limit for self-study examination (no more than 8 years). It is recommended to finish the exam in two years. General self-taught college 16, undergraduate 14. You can apply for graduation as long as you have passed all the courses. You can apply for classes if you have the conditions.