Toddler's meltdown

Hi guys, my LO is 18 months and everytime we told her not to do some particular things, she will scream bloody loud then throwing tantrum by crying out loud.

We just had the first experience to have holiday and she walked around a lot. Then, we decided to go back to our room and she refused to do so. When i picker her up, she just screaming out loud and i feel so ashamed because people were looking at us.

It happened also when she wants something and we are not fast enough to get it for her. She will scream also.

Do you guys have any tips how to handle this? I am worried she will be a spoiled girl.