Welcome to the Ranch!
Can you try calling Maven from the command line? Just try
mvn package. That will compile your code, run any
unit tests you may have, and create the JAR file. Maven will tell you what's wrong. If you still don't get enough information, use
mvn package -X -e instead. You're going to see all of Maven's debugging information, and the exception that causes the build error.
Can you also post the contents of your settings.xml? You can find it in your home directory, folder
.m2. It may not be there, in which case you'll only get default settings (but those should suffice for building in most cases).