There are no easy answers to your questions.
You need to figure out exactly what you want to sue for. If you are thinking about handingly this yourself, then I would definitely think about trying to file the claim in small claims
court, which has a $5,000.00 limit but is based on forms and does not require a lawyer. This would be a suit for breach of contract and negligent misrepresentation asking for the cost of repair of the vehicle. To file this suit, you would go to your local small claims court and pick up the claim forms to fill out.
If you are going to sue for the return of the vehicle on a fraudulent inducement basis, you really need to hire a lawyer to file the lawsuit for you and represent you in court, as this kind of lawsuit cannot be filed in the District Court
small claims division. Rather you would file in the general division of the District Court or you would file in the Circuit Court
(if the claim you are making is for more than $25,000.00). There are no forms per se for this type of lawsuit which are free on line. Rather there are examples on line or you can go to a pay for form website like legalzoom, etc., to get a form for this particular kind of claim. You will have to review and understand all the pertinent Rules of Civil Procedure
when making your filings, doing discovery, etc., and when and if you make it to trial, you will have to know the Rules of Evidence. The courts do not waive these rules just because you are not a lawyer, and you will be held to the same standard as a lawyer when before the court.
In regard to the demand letter, here are some examples/forms: