drag and drop the section in 1x1 layout and apply read-only on the cell...

You can make the entire section as read-only using the Update privilege.

Drop any section in another parent section, open the properties of the layout. You can find an option called "Update privilege"

what is privilage which we need to choose in update privilage ?

Create your own privilege and use it

We can hide our section by using Privilege  Action.

As you drag and drop and section you will be seeing the properties panel of that section where you can see the Update Privilege.

If you want to make it ready only all the time you can use OOTB Never Privilege.

Regards,

Sunil P