Have you tried running Illustrator without any third-party plug-ins/extensions installed?
Does it work then? If yes, then you're likely looking at an incompatible plug-in/extension that's installed. Contact the manufacturer of that extension to confirm it has been tested, or supports with Illustrator CC (2018).
It could also be you are working with some corrupted fonts? Are you able to reinstall the fonts from their original installer files?
If you can't resolve the issue pls try to provide a bit more information:
* Operating System, version etc.
We can then direct you to where crash-log files are stored, as possibly reviewing those would help identify the issue.