What are your best tips for early behavior lessons? I'm not sure the best way to phrase this at 7am, lol.

For example, LO is already screaming to get his way. He screams when we leave the room and he'll scream at the door when we put him down for naps hoping we'll come back in (not every time). He won't sit still in the bath, tries to climb all over the place. And what do you do when he puts something in his mouth that he shouldn't? I can't elevate and hide everything.

I know there will only be more, so what are your tips that worked for you this early on?