First hadoop project error: "Input path does not exist"

You need to upload your input files to the HDFS file system first:

bin/hadoop fs -mkdir In

will create a directory named /user/DEVUSER/In in HDFS.

bin/hadoop fs -put *.txt In

will copy all *.txt files from the current directory to the cluster (HDFS).

You seem to have skipped the chapter Upload data from the tutorial. Follow it and your problem should be solved.

First hadoop project error: “Input path does not exist”