I would recommend trying out Snow (https://snowemu.com/), a somewhat recently released 68000 Macintosh emulator that is cross-platform and focuses on low-level accuracy, unlike prior efforts which traditionally preferred HLE approaches and suffered from compatibility issues as a result.

As with any other emulator, you will have to obtain system ROM dumps and disk images of the software you want to run. There is no clear precedent on the legality of acquiring said files through any means, however it's generally believed that you should be in the clear if you dump them yourself from a Mac you own and an original physical copy of the software. Of course, doing so is non-trivial and requires at the very least a working Mac and a way to get files in and out of it (e.g. a SCSI drive emulator that uses an SD card for storage), so it's understandable why virtually everyone resorts to the gray area approach of downloading ROMs instead.