How can i show or hidden secctions and field when pick a Multiple Choice option?

Assuming you're on a form - you would navigate to the 'Form Rules' section of the form. 

The 'condition' in your form rule would be to check on the value of your MC field and the 'action' in your form rule would be to show/hide sections or fields. You can have multiple actions as well if you need to hide multiple sections or multiple fields.