/usr/local does not exist by default.
To create it, from the terminal type:
sudo mkdir -p /usr/local
Have you verified that Maven is installed correctly?
Run mvn --version to verify that it is correctly installed.
When you exported the variables, did you adjust them for the new paths required by not using /usr/local? Can you post the output from
echo $M2_HOME
echo $M2
echo $JAVA_HOME
echo $PATH
Cheers,
Joel