The best way to keep spam at a minimum is to never publicly publish your email address. But if you have a public email address, or you've had an email address for a long time, you are almost guaranteed to receive spam as some point. There are two broad classes of spam filters: server-side and client-side (in your email client). We recommend that you enable both types.
The server side spam filter can be configured quite easily. First login to your cPanel, then click on Spam Filters under the Email section. Here you can enable spam filtering by turning on Process New Emails and Mark them as Spam.
You can then set the aggressiveness of the server spam filter by clicking on Spam Threshold Score and setting a level. A setting of 5 is generally recommended. It strikes a good balance between not rejecting legitimate email and filtering most obvious spam. If you need something more aggressive a setting of 3 or lower will catch most spam, at the risk of potentially catching some legitimate mail that looks similar to spam. After setting a score, you can click Overview to return to the mail spam filter settings.
Finally you can enable either Move Spam to a Separate Folder (which requires an IMAP mail connection or webmail to access) or Automatically Delete New Spam. If neither of these options are set, the subject line of the spam messages will be changed only and no actual filtering will take place.
Client Side Filtering
Most modern email clients support spam filtering. Typically you mark messages as 'junk' or 'spam' and your email client uses a special learning algorithm to predict and automatically filter future spam messages. Usually such messages are moved to a special folder called 'Junk' or 'Junk Email'. For more information about using the junk mail feature in your email client, please refer to these vendor support articles.