how much time i should spend in studing

It really depends on your energy level.
The amount of time you should spend studying depends on how many classes you are enrolled in, your personal study habits, and your educational goals. As a general rule of thumb, most professors suggest that college students spend about two hours studying per week for each credit hour they take. However, recent studies have shown that most students only spend one hour studying per credit hour—just half of what is recommended to be successful. Most college courses are three to four credit hours, so this means that for each class you should spend about six to eight hours studying. Full-time students should anticipate spending about 30 hours each week studying. To many students, this can seem overwhelming, but if you manage your time correctly, your studying will become more productive and will help you perform better in both traditional and online courses.