Firtly, choose your Updates page to assign it as posts page from your site’s dashboard (/wp-admin) > Settings > Reading > Your homepage displays.
In the same settings page, you can set how many posts to show in the list from the Blog pages show at most option.
Update the settings.
Afterwards, go to Appearance menu > Customize > Blog options; and enable ‘Masonry (grid style)’ blog layout. Hit Publish button to save yout recent change.
That’s it. I hope this reply helps.
Let me know in new topics for your other questions. Please note that we encourage you to use one topic for one question, so we can track each progress easier and maintain our support forums in good order.