How to keep toddler under control in public

We have a 2 year old. She will actually be two next week. Sometimes she’s good in public but a lot of times she’s not. For instance, we go out to eat a lot. She gets SO mad when we don’t give her our cup to drink what we have (even when she has a full cup of her own) or like yesterday, she screamed her head off in the middle of a restaurant because my husband wouldn’t give her the phone. She’s still at the age where she doesn’t understand words like calm down, be quiet, and things like that. We try our best to calm her down but it does work. Then she began throwing things, spitting, etc. I took her outside 3 times and when she calmed down I told her she was a good girl and we went back in.

And another example is when we go shopping. If she’s in a cart, she screams because she wants to stand up. We don’t allow it. Or if we are somewhere where we have to hold her hand or hold her, she screams because she doesn’t want to hold our hand and will throw herself on the ground and have a full on temper tantrum. We have a baby due in a few months and I really want to get this under control.

We discipline her as much as we can. We don’t give in to what she wants. She always has toys or snacks wherever we go so she’s occupied but she just doesn’t listen to anything.