If you are asking these questions you are in over your head. If you are the defendant or plaintiff and you are facing an attorney--you are going to have your backside handed to you--get an attorney, at least consult one (that means all the details of your case, not just a selected question) before you get any further along.
NOT LEGAL ADVICE. FOR EDUCATION AND INFORMATION ONLY. Mr. Rafter is licensed to practice in the Commonwealth of Virginia and the US Federal Courts in Virginia. There is no implied or actual attorney-client relationship arising from this education exchange. You should speak with an attorney licensed in your state, to whom you have provided all the facts before you take steps that may impact your legal rights. Mr. Rafter is under no obligation to answer subsequent emails or phone calls related to this matter.
I don't understand the part of your question about copyright. Generally speaking, in states in which depositions are a discovery device generally utilized by parties in civil litigation, a party to the litigation is entitled to depose other parties to the litigation, and parties to the litigation may not refuse to be deposed. A pro se plaintiff will be required to submit to deposition, and the plaintiff may depose other parties to the litigation, as well as third parties who are subject to the jurisdiction of the court.
Not legal advice as I don't practice law in Ohio. It's just my two cents responding to the facts you describe and discussing a general principle of law. If you need legal advice, please consult a lawyer who holds Ohio licensure and who is knowledgeable about Ohio litigation practice. That's not me as I practice in Vermont ONLY.
You need to learn the rules of civil procedure and rules of evidence if you are going to attempt to handle a lawsuit on your own. Ohio Civ. Rule 30 allows any person, including a party, to be deposed. If this is a copywrite related matter, you should immediately consult with an intelectual property (IP) lawyer.
If the deposition is noticed and the notice period is reasonable, you must attend the deposition and answer their questions. Discovery is quite broad. They are permitted to ask questions that could potentially or arguably lead to the discovery of admissible evidence. Failure to attend could result in dismissal of your claims or other sanctions by the Court. You really should obtain an attorney in such litigation. You have the same right to notice the deposition of a party, or if the party is a business, to notice a representative of the business to testify on certain subjects. That part gets tricky and needs to be noticed properly. But assuming you are noticing a party and that party is an individual, you give notice of the time and location of the deposition and then you call a court reporter and make sure you have a court reporter present to take down their testimony. This will cost about $300 to $400 and more if you want the deposition to be printed out or to receive an electronic copy. Taking a deposition is very important in the case and you need to understand the purpose of a deposition and how to use the deposition at trial. These are matters that are very technical and should be handled by an attorney. Good Luck!