Copy paste issue & Error show before illustrator open

@swapnil35891614xmsu it's likely to be caused by a corrupted Illustrator preference file or a bad font that the application tries to load on startup. Illustrator's preferences can get damaged, especially after a crash. Quit out of Illustrator again. Hold down Control Alt Shift (PC) or Command Option Shift (MAC) immediately after launching Illustrator. You'll be asked if you want to delete the preferences file. Say Yes. And restart Illustrator.

If that didn't work, a corrupted font file on the system can cause Illustrator to crash or show errors on launch. Run a font manager or a system font checker to validate and remove or disable any corrupted fonts. You could also try launching Illustrator in Safe Mode (if prompted) and running diagnostics to identify the issue. 

For the copy and paste, a common fix is related to how Illustrator handles clipboard data. Go to Edit - Preferences - File Handling & Clipboard (PC) or Illustrator > Settings/Preferences > File Handling & Clipboard (MAC) and uncheck the option "Include SVG Code on Copy."