Plan to study about double your year of study in hours each week
A UJ academic development director gives a simple rule of thumb: spend roughly double the number of hours of your year of study on your own work each week, which works out to about 26 hours a week in first year. It is a rough guide, not a rule, but if you are well under it, that is worth knowing early.
Source: https://www.up.ac.za/news/help-im-first-year-tips-making-most-of-your-time-student