It is not easy for everyone to go for a checkup since it will cost a lot. Having a free checkup at school can actually easier than later. It is better to look out for it at a young age than waiting for you to get older for the testing.
This could be very beneficial for the young people who are possibly too shy or anxious to make that phone call or enter that clinic. It takes away the societal burden over contracting an std while testing in a safe and supportive environment. It is not a premonition of being involved in sexual acts it is just there as a support system for those who chose to do so, By having this it encourages safe sex and promotes the idea of it not being unacceptable or a sin to do so.
Of course we should be teaching young people about sex and the danger of STDs. And as a young person I agree and see the purpose. But offer STD testing is a bit of stretch. Why should pay tax-payer go in something like this where go into stuff such as STEM subjects. Because isn't hospitals and healthcare facilities responsible for providing these things? Yes, If Young People think they have a STD we encourage them to get tested but it should at a hospital or a sex health clinic, A place where these things are better known and recognised. So I say the place for STD testing should in the hands of Doctors not High School Principals.