how to stop or prevent my 14+mths old from biting people?

I really feel you on this, it can be so stressful especially when the school keeps reporting incidents. My boy went through a biting phase around the same age and what helped us was giving him something chewy to munch on before school, like a soft snack, so his gums had some relief, and we also kept reinforcing "no bite" firmly and calmly each time it happened at home so he slowly started to connect the message. Since he has so many teeth coming in at once, the discomfort is probably quite intense lah, so it may ease up once that wave of teething settles down.