As the error states, the target directory you have mentioned in the sqoop command already exists in hdfs. So, in the sqoop command, in the target dir parameter, mention the directory that is not already present in hdfs. The sqoop command creates the directory automatically. Now you can either give a new name for the directory, or delete the existing directory and then run this command again.
Refer this link to delete the directory: https://www.edureka.co/community/38015/deleting-directory-in-sqoop