It all depends. Generally, when people wear soft contacts for the first time, they should wear them 2 hours in the first day, 4 hours in the second and 6 hours in the third day to get used to them. From the fourth day, they can wear them about 10 hours as the common time. So, most people adapt themselves to the lenses for about three days. If you can not get used to them in three days, you'd better wear them less than 8 hours in the next week to make them work well. As for how long can most contacts stay in your eyes, I mentioned that 10 hours are many people wearing contacts per day. If you really have something to do, that means you do not have the chance to take them out within 10 hours, you'd better take them out in the 12th hour. Or they may cause eye diseases for you. By the way, please do not wear them when you having a long sleep. If it is a nap, it's OK.
It really depends. For people who have get used to some common contact lenses, they can also easily adjust to the soft contacts. If this is your first time to wear contact lenses, you need to consult the professional technicians how to wear contacts correctly. Then, when you come home, you should practice wearing them by yourself and do as the technician has told you. Remember to wear the contacts several hours a day, but not too long. After several times of practicing and wearing, I believe you will get used to your soft contacts. Good luck and hope this will help you.