thinking of wearing a Rudraksha on Maha Shivratri please help

hey everyone I am a student who will start his bachelors this year and I have done a lot of research to wear a Rudraksha on this Maha Shivratri and first I thought of getting the Saraswati bandh and I bought it but I read it on google and one yt video told its for 18 or less and Ganesha Saraswati bandh is for people above age 18 so do I need to get the Ganesha Rudraksha ? and what more should I consider from kundaali it suggests 7 mukhi as my Lagna Lord is Shani dev