Change owner for all folders and files in a folder

sudo chown -R user:group /path/to/dir/

Where user is new owner, group - new group of user.

-R indicates that the operation must be run recursively.

Changing the permissions to the file or folder

chmod -R 700 /path/to/file/or/dir

-R indicates that the operation must be run recursively.

Changing the permissions only for files

find /path/to/dir -type f -exec chmod 600 {} \;

Changing the permissions only for folders

find /path/to/dir -type d -exec chmod 700 {} \;