Recommended secure permissions for files is 644, for folders 755. So your 744 permissions looks good and a little over-secured.
You can change permissions for whole project with this commands
find . -type d -exec chmod 755 {} \; find . -type f -exec chmod 644 {} \; 644 means that files are readable and writable by the owner of the file and readable by users in the group owner of that file and readable by everyone else.
755 is the same thing, it just has the execute bit set for everyone. The execute bit is needed to be able to change into the directory. This is why directories are commonly set to 755.
If you have some login information in php file, like for db, I would recommend set it to 600 to prevent reading by other users expect owner.
Setting all php files to 600 makes no sense, because there is nothing secret, especially for CMS like Wordpress. But it can cause more troubles in support.