Should I contact my Half Sibling?

Hello, I'm a 45 year old adoptee and I'm interested in contacting my Bio-Father who I believe is still living. I've done some searching and he is very difficult to find any information on. I did however come across social media accounts for a couple of his other children. Not sure if it would be appropriate for me to contact the half siblings through social media because I don't know if they are aware I exist. Looking for some guidance on this one because I don't want to cause disruption. Any feedback or advice is welcome....thank you