Hi jslims,
First set the ‘coming Soon’ page that you have created to the ‘Homepage’. To set the desired page to the ‘Homepage’ go to ‘Appearance > Customize > Homepage Setting’ and check ‘ON’ to ‘A static page’ and set the Homepage by choosing the desired page from dropdown list. After it again go to ‘Appearance > Customize > Additional CSS’ and paste the below Custom CSS code.
.site-header,
.site-footer {
display: none;
}
Note: the above mentioned code will hide the Header and Footer Section on the Theme so if you wish to show the Header and Footer section again then you can remove the mentioned code again.
.
.