I would like to ssh to the instance of the terminal

Sure, you can ssh to the terminal while terminal is up and running. Storage has username and every time terminal is up, domain name is to be associated to the terminal, which is <storage name>.wazaterm.com. Add your ssh public key to ~/.ssh/authorized_keys file, then you should be able to access to it.

# Open authorized_keys and add your public key
$ vi ~/.ssh/authorize_keys

So, if you have ssh then what? Yes, you can use scp/sftp/sshfs :)