In order to get your child into school in Spain, follow these steps:

Identify the area where you live. In Spain, compulsory education is provided by public schools distributed by districts. The choice of school will depend on your place of residence.
Find the nearest public schools. This can be done using online resources, local ads, or by contacting the municipality.
Visit the selected schools. It is recommended to familiarize yourself with the conditions and capabilities of each school, communicate with teachers and administrators, and view school premises.
Collect the necessary documents. Usually, a passport or residence permit, a child’s birth certificate, a medical card and vaccinations, a residence permit (certificate of registration in the municipality), and photographs of the child are required.
Apply to the school. This usually happens at the end of each academic year or at the beginning of the next. Fill out the required forms and provide the requested documents.
Go through the interview. Some schools may require a meeting with parents to clarify additional details.
Expect a notification from the school. You will be informed whether your child has been accepted to school or not. If your child has not been accepted to the chosen school, you may be offered another school that has free places.
Visit the school on the day of the start of the school year. You will be provided with a schedule, a tour of the school and will be introduced to all the necessary aspects of the child’s education.
Please note that the procedure for enrolling a child in school may vary slightly depending on the region and the rules of each particular school. Therefore, it is recommended to contact the local education authorities or the school to get additional information and a referral.