Hi,
A "normal" file sharing is not possible since AppleTalk is not used with modern Macs.
Instead, two different methods (as described in the articles below) may be of interest. They work with modern Macs or PCs.
https://happymacs.wordpress.com/2014/07/12/network-your-classic-macintosh-with-windows-part-4-using-web-sharing/
https://happymacs.wordpress.com/2014/07/09/networking-your-classic-macintosh-with-windows-part-3-using-netpresenz-and-fetch/
Avoid a direct (crossover) cable connection. It is easier and better to connect by Ethernet cables via the LAN ports of a Wi-Fi router. Power cycle the router, and then the computers.
The web sharing method above works one way (from the old to the new Mac). The FTP server method (NetPresenz on the old Mac) should work both ways with an appropriate FTP client on the new Mac.
Use these methods locally only.
Alternatively, for transfers from a new Mac or PC to an old Macintosh computer, one can burn a CD-R (not RW) disc in an ISO 9660 format at a low speed. Any downloaded Macintosh application files for Mac OS 9 must stay protected (typically, encoded MacBinary or BinHex) until on the old Mac. Once there, a suitable StuffIt Expander version can be used for decoding (drag the files onto the StuffIt Expander program icon).
