It's not clear what you are doing. If you are trying to read a DAT file then you are going to need an INFILE statement and INPUT statement to read this. I don't see these statements anywhere in your screenshots.
You can only use a SET statement to read an existing SAS data library. Your MYFOL library needs to be defined by a LIBNAME statement before you can use it.
Please post SAS logs using copy and paste, not via screenshots.
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