How to configure varnish in magento 2?
Selecting Varnish Cache in Stores Configuration is enough?
Selecting Varnish Cache in Stores Configuration is not enough. You also need to install Varnish on your server. You can refer to the following link to install Varnish with Apache on Ubuntu.
After successfully installed Varnish Cache, you can configure it from magento admin configuration
STORES > Configuration > ADVANCED > System > Full Page Cache.
Please check with below step :
Log in to the Magento Admin as an administrator. Click STORES > Configuration > ADVANCED > System > Full Page Cache. From the Caching Application list, click Varnish Caching. Enter a value in the TTL for public content field. Expand Varnish Configuration and enter the following information: Click Save Config.