The following code can be used to set the default value of a field.

This code allows you to build if statements in a View to check if the current user is the creator of the entry. Use [if 100 show=ID is_current_user=1]content here[/if 100] to conditionally show/hide specific content based on whether or not the user currently viewing the display is the owner/creator of that entry. Change 100 in your shortcode to the ID of your user ID field. Then add this code to your theme functions.php or a new plugin without any changes: