Initially, it will be difficult to manage study time during college life because the transition from high school to college will be new to the students. They are no more guided by strict school teachers and they feel they got wings to fly with so many distractions around. This is the time elders at home should guide them on how to manage their study time.
Have a proper calendar system. Either note down on a paper or maintain a digital calendar.
Note down the deadlines for your semester. Sketch out the schedules for all the courses and due dates to complete assignments, examination dates etc., and work according to them.
After having a semester wise schedule, further, break it down to a weekly and daily to-do list.
Create deadlines and try not to miss them. You can prioritize your daily tasks according to their importance and work toward accomplishing them.
Once you create this type of schedule, try to follow it very very strictly for the first two-three months. Later you will get used to it and you can automatically adjust your priorities.