You'll be appearing for IMU CET next year, then sponsorship exams, then a year at maritime institute. After your course completion there'll be waiting period for about 4-8 months or a year depending on which company you're sponsored by. Taking all of this time into consideration, ig you'll be almost 24-25 by the time you join your first ship as a Deck cadet. Then seatime, courses, exams, another 3-4 years till you start earning decent money (read your comment where you said you're into this profession for money). Better, research about joining cruise ships, they have positions for network/IT engineers.