If your old Mac is completely dead, there is really no way practical to recover the data. If it's just the display or keyboard, you can connect to external versions of those. But if the Mac cannot be powered up, the data are effectively lost because the SSDs are integrated into the logic board and power is required to access them.
If you don't have a backup to use as BobTheFisherman suggests, you'll have to start over. This time, best to maintain a backup. Apple provides an excellent utility for doing so, the recommendation is an external drive that's 2-3x the size of your internal storage. A 1 TB SSD is fast and <$100.
Back up your Mac with Time Machine - Apple Support