Eclipse Installation on macOS
Eclipse on macOS will not start with Java 14 installed, this is being tracked in Eclipse bug 561273.
Installing Java 8 as well does not help. You need to remove the Java 14 install. You could use the Java 13.0.2 release instead.
Eclipse have determined that the root cause of this issue is a change in Java 14 which is described in this bug report JDK-8238225. The fix for this should be in Java 14.0.1
Update: Eclipse runs fine with Oracle Java 14.0.1 so the issue has been fixed.