Hello,Welcome and thanks for your question. We get a lot of questions like this. Adoptions are almost always closed legal proceedings. To learn who your biological parents are, you need to get an attorney to petition the court to open your adoption file so you can learn more about the biological parents. When someone is adopted, the birth certificate is generally changed to show the names of the adoptive parents to protect the identities of the biological parents who have given up the child (for whatever reason). Often the court requires a medical reason to open the file.
Some other things you can do is register with web sites that seek to reunite children with biological parents. Here is one in Ohio http://www.adopteeconnect.com/p/a/1038/ You might get lucky if your biological parents are also looking for you, but it's a long shot.
Here is another site that has some information specific to Ohio:
Good luck in your search.
All the best,