Hello,
Watery eyes at your age can be due to eye strain(due to excessive screen time) or uncorrected refractive error or allergic conjunctivitis.
Next Steps
kindly get an online consultation, we can have a look at your eyes first. For correction of refractive error ,you will have to visit an eye clinic nearby.
Health Tips
Take adequate breaks every 30 minutes,while using screen
adequate sleep
wash eyes with cool tap water twice
you can use lubricant eye drops available in the pharmacy.