If you need to change permissions for all the files or all the folders in a specific directory, then you will need these commands:
For changing files’ permissions:
find /path/to/directory -type f -exec chmod 644 {} \;
For changing folders permissions:
find /path/to/directory -type d -exec chmod 755 {} \;
Or, you already changed the directory to the desired path, you can use these commands:
For files:
find . -type f -exec chmod 644 {} \;
and for directories (folders):
find . -type d -exec chmod 755 {} \;