Generally speaking, statute of limitations begin when you should have known there was a legal dispute. Each state is different, but most provide at least one year. You need ask an attorney or research the law for contract dispute statutes of limitations in your state.
In Washington, oral agreements are subject to a 3 year statute of limitations. But even if three years has expired since you made the loan, any payment, and statement of acknowledgment of the debt, or even a question about a payment extends that 3 year period. So if you have an email within the last 10 months from the persons to whom you loaned the money, you should not have a statute of limitations issue and you can proceed in small claims court, but subject to the rules of that court.
Best of luck.