Before you consider one of these apps, you might be able to get your Mac up and running so you can perform that backup you should have done. Read: How to recover data from a damaged Mac. And speaking of backups, you might like to read: The best backup software for Mac and How to use Time Machine to back up a Mac.
Key attribute of an ideal mac data recovery software : Compatible with the latest operating systems such as macOS Mojave, High Sierra.