By default Wordpress assigns the 755 permission and in its documentation the recommendation is that you do not need to change the settings it assigns by default.

What you need to worry about is that you should leave the default 644 to wp-config.php or if you prefer more secure security you can leave it at 600 (test to see if it will not give your installation a problem) .

Also leave 644 for .htacess or 604 (some plugins may need at least 644 .

Another important point is to not allow permissions 777 because it leaves fully writable, where it can be a port for hackers and malicious files.

Check the official documentation:

- Changing File Permissions

- Shielding WordPress