To prepare the application for work, you need:
you need to create mysql database with name 'car_rental_spring';
CREATE DATABASE car_rental_spring;
you need to customize your application.properties file:
{
#for connect with your MySQL server
spring.datasource.username=
spring.datasource.password=
#for javaMailSender spring.mail.host=
spring.mail.username=
spring.mail.password=
spring.mail.port=
spring.mail.protocol=
mail.debug=
}