This is all covered in the doc and the tutorials. It will be very helpful for you going forward if you review these
Lets say you want to read all files in a dir and print their content to the console. to do this you would set up a job like this:
tFileList_1--iterate-->tFileInputFullRow_1--row-->tLogRow_1
in the tFileList you would put in the directory you want to scan for files and a file mask if needed.
in the tFileInputDelimited you would make the filename a call to the globalMap which is where the tFileList stores the current iteration's filename. for example: