In the WP Google map plugin metabox are used to create locations in map from post and page. By default metabox enable in your Google map plugin.You can hide meta box from post and page in 2 ways:

From Posts or Pages

Step 1Go to Posts or Pages in the dashboard.
Step 2You need to use the screen options at the top of the posts/pages and unmark ‘WP Google Map Pro’ box.

Then you’ll see metabox hide from your posts or pages.

From Google map setting

Step 1 Go to WP Google map > Setting.
Step 2 Mark the checkbox of ‘Posts’ and ‘Pages’ in ‘Hide Meta Box’ option.

Meta Box Hide

Step 3Then click Save Settings. Now you’ll see metabox hide from your Posts and pages.