Hello,
I also started my installation of Accumulo today and ran into some of the same issues and after a wild goose chase through the system I was able to run the system with a minor issue dealing with configuration of the tablet severs.
I am using the 2.2.4 version of Hortonworks Sandbox.
I found the configuration file accumulo-env.sh to be found /etc/accumulo/conf directory to change the variables, the ones you need to configure here is the $HADOOP_HOME, $JAVA_HOME, $ZOOKEEPER_HOME, AND $ACCUMULO_HOME.
I found that none of the variables but $JAVA_HOME gobal variables are not set.
you can find zookeeper, hadoop, and accumulo in the /usr/hdp/current directory. then the appropiate names zookeeper-server, hadoop-client, and accumulo-client for each.
I still have issues running the shell and connecting to zookeeper, but this is as far as I have gone. I hope to either find the correct home paths or set up the tablet servers correctly. Best of luck to you.