Discipline help!

I have 2 children I care for with very active personalities and I need some help. I’ll explain them both separately.. sorry for the reading involved!

J is 2 years old and my fiancé’s son. He’s being raised by tv at his moms house and doesn’t listen to the rules at ours. Yesterday I had a really hard day and my fiancé’s grandmother helped out, but she wanted to take us to McDonald’s. Fine ok, I’m grateful for help. Well he immediately took off running in the restaurant and bolted into the play place where he climbed up the tube, and hid up top. We where there for 2 hours because he would NOT come down. I spent a vast majority of the evening getting dirty looks from people eating because he was running around and screaming. Terrible twos am I right? I don’t know how to handle this kind of situation. My fiancé’s grandma tried to bribe him with a cookie and juice and toys and I was at a loss of what to do.

Second child is a little girl I take care of for work. She’s 4 years old and has a bad “accident habit” (she’s constantly going to the bathroom in her pants.) she also refuses to listen to anything. Yesterday she grabbed a cookie and licked it while I was putting her brother in a high chair, and after I told her she needs to ask first and that she’s not allowed a cookie because of her accident (her parents rule I have to enforce) she stuck her tongue out at me and shoved it in her mouth. She then spit water all over the table and when I asked her to clean it up she yelled “shut up poopoo head” I’m supposed to enforce quiet times when she refuses to listen so when I asked her to please go upstairs she screams and runs. I carry her upstairs to her room and she immediately bolts around me and down the stairs or she punches me in the face the whole way up. I reallllly don’t know how to handle these situations.

With the 2 year old I can understand that he’s excited and he doesn’t understand, but the 4 year old is another level that idk how to deal with. Any help is greatly appreciated ❤️❤️