You need to find the amount of valence electrons that the element has in order to do a Lewis structure.
For example since Calcium has 2 valence electrons, i put two dots around the element symbol. You also can’t have more than 2 dots on 1 one of the element. Each element has 4 sides like a box.
Here are some great videos that explain it in further detail.
https://youtu.be/Sk7W2VgbhOg
https://youtu.be/Z6Hx_BAZeUw
