Hello sir, yellow teeth is not a problem as such your actual teeth color is slight yellow reason is your teeth has 3 Layers first is enamel which is considered to be white second layer is dentine so usually ur dentine is yellowish is color and it is always shown through your enamel, which is normal no need to worry .
Next Steps
if cc ccyou feel it's yellow then u need to consult you dentist to get your yearly cleaning and polishing that will give good results
Health Tips
your too young for all the bleaching and whitening tpptreatment so don't attempt it now.