How can I find my biological dad

I'm adopted. My mom adopted me as a single women. I love her more than anything but I have really wanted to meet my dad. I was interested in really having a huge relationship with my biological mom because I already have a mom. I'm not looking for another one but I was able to find my biological mom easily because she left her information open. However when I reached out to her about the where abouts of my father she said she didn't know who my father was. I asked if she knew the men she may have been with around the time she got pregnant with me and apparently it's A LOT of men...... She gave me the Facebooks the names she knew for SURE she slept with and it was like 14 dudes. I'm not going door to door to find out if this dudes are my father and she slept with way more than 14 so there's a chance none of them might be. Bio mom was so help at all so. I was wondering if anyone knew how else I could find him.