Thanks for taking the time and effort to inquire about study skills. As another tutor expressed, be patient with yourself (After all, you took the first, and arguably the most difficult, step in asking your question.)
Regarding Study Skill, Time Management, Organization and Prioritize Skills seem to be be highly effective.
Time Management might be the most tangible as well as straightforward technique. Having some type of schedule in sight, such as a calendar, weekly planner might give you an idea of the week and help plan accordingly. Some students including myself find it helpful to color code my schedule, filling out certain times reserved specifically for studying, work, leisure, etc.
Organization: A common pattern among successful students seem to be strong organization skills: Knowing when tests and assignments are due each week help promote academic performance. Some have found Post-it notes to be effective Reminders.
Prioritize: One technique that might help alleviate the stress of college workload is prioritizing your assignments using a timer. Some start by creating a list of all the upcoming assignments, then arranging assignments in order of their importance. Then setting a timer to complete the list of assignment in chunks of intervals might increase efficiency.
I can elaborate if anything was confusing. Hope that helps!