My 9 month is starting to show is true colors by giving us a lot of attitude in a way. He's been…

My 9 month is starting to show is true colors by giving us a lot of attitude in a way. He's been hitting us, and grabbing our face which hurts honestly lol. I understand they don't know what "no" means. We're starting to teach him. What are some tips you mamas can give me? He's been apt fussier and whining a lot due to him teething as well.