Thanks for the thanks.
My quick solution assumed that you have "JOB INPUT NULL", ie you are doing the reading yourself, but basically just reading the main file.
If you are reading some sort of subsidiary file, then
IF RECORD-COUNT (FILE1) NE 1
PERFORM whatever-file-processing-you-want
END-IF
Why do you want to ignore the first record? If it is a file header, it would be better to identify it as such, and ignore it specifically because it is a file header, rather than just the first record. The file header may (should) have data on which you can check in the program that you are reading the right file (right day, right name, whatever). If there is a file header, is there a file trailer? If so, should identify it and again verify any data on it (record count, total of any fields (hash counts)).
It may seem a waste to do all this stuff, but it can save you a lot of time, and once you have your first program working, you can "clone" it for the next one, so don't have to repeat the coding of the header/trailer each time, just the checking.