Because copyright protections attach automatically the moment a qualifying work is created, you unquestionably already own copyrights. There may also be some works that you created, but that belong to your employer (if you created them on the job), or to someone else (if you transferred them away, as in a publishing agreement.)
People commonly have questions about ownership and copyright around issues such as:
...ownership issues in your scholarship, including dissertations, theses, and student works.
...how to deal with suspected infringement