Yes, you have to change the permissions of the directory as well.
This is because if you only have write permissions to the files inside the directory, you can't just create a new file because you don't have write permissions for that file (it doesn't exist, so no permissions to create it).
If you have write permissions for the directory you can create a file inside it because you have write permissions for the directory itself.
To make yourself the owner (terminal way):
Check your user name:
Make yourself the owner of the directory and its contents:
sudo chown -R username:username /path/to/the/directory
username by your actual username.
-R flag stands for recursive, so that directory and all its subfiles and subdirectories will change owner. Remove the
-R flag to just change the permissions of the directory itself.
Now you should be able to create files or directories because you're now the owner of the directory and all its content. If you still can't, give the owner write permissions to the directory and its content using the following command:
chmod -R 700 /path/to/the/directory