Search the internet for the FTP Apple Asimov server (there are http mirrors if you don’t want you use ftp). This is an archive of many thousands of Apple diskette images and software.
Download stuff from the archive onto an SD card. Then purchase an SD to Apple disk emulator card (plugs into one of those 7 slots and emulates an Apple disk drive). You can load software from the sd card onto the Apple just as if each file from Asimov were a real 5.25” diskette.
Also pick up one of these:
https://www.cbmstuff.com/proddetail.php?prod=WiModem232OLED
You can connect your Apple to WiFi and then essentially telnet to one off the many BBS servers that are still running. Actually you can telnet to anything on the Internet at that point. You just need to load terminal emulation software, like Ascii Express (often abbreviated as AE or AE Express), onto the Apple first.