What visa should I apply for my second son who hasn't chosen a school yet while we are in Thailand on student and guardian visas?

The user is seeking advice on what visa to apply for their second son who has not yet selected a school, while currently in Thailand on a student and guardian non-educational visa. Suggestions from the community include applying for a single-entry tourist visa which is valid for 60 days and can be extended for an additional 30 days, providing time to secure enrollment in a school and later transition to a student visa without leaving Thailand.