Hey,
The default zookeeper installation (tar extract) comes with the conf file named conf/zoo_sample.cfg while the same extract's bin/zkServer.sh expects the conf file to be called zoo.cfg thereby resulting in a "No such file or dir" and the "failed to write pid" error. So before starting zookeeper, make sure you provide the actual path for
zkServer.sh
Try follow this command:-

You will get an output like this:-
Hope it helps.