The DE10-Nano MiSTer system can be accessed through the on-board Ethernet port. The MiSTer system has FTP, SSH, SFTP services running.
User name: root
By default, DHCP is used to acquire IP address for the board. You can find it from your router (easier way), or from the console connected to the board using the command ifconfig.
If you need to set up a static IP address – please follow the Linux manuals (/etc/network/interfaces changes)
mc (midnight commander) file manager is available for easier folder navigation.