Advise please 😰

I’m a first time mom and when I ask people for advise I feel like they just save my feelings. Our son has always been a very sweet loving baby. But lately he’s been hitting, biting (mainly me) and throwing everything! He does do this in an angry way sometimes, others he being playful. My question is, how do I discipline him. Do I pop his thigh, I i sternly just say no, do I put him in time out? I’m lost, help! I know this is a phase but I guess I need reassurance I’m doing something right 😂😭 (And yes, he has been teething lately.)