The first thing is to decide which platform or crowdfunding site you want to use. I have listed some in this article that you could start with. See which one is best suited to your needs. Then begin to promote. This will be locally and on social media channels. Contact businessmen in your area, who can help you promote to a larger audience.
Although there are sites for one-off payments, look at potentially doing one that is on going, as schools always have a need for cash. Patreon is one site where you can have an ongoing payment system. You would need to update it frequently, but if you were to highlight school and village/town activities, you may do well.
When you go to any of these sites, they will show you examples of campaigns that have done well, and give you free advice on how to make yours successful.