Yes. From both the control panel and the hub you will have access to a file manager tool for each of your sites. With it you can create, edit, and delete files belonging the wordpress site and environment. 

You can also manage files for a particular site using an SFTP desktop tool such as FileZilla or Cyberduck. You can connect either of these tools or any other SFTP tool to a website using the SSH credentials which can be found by navigating to the particular site within the control panel.