You have a file with one or more header lines and you need to process just the data, and skip the header.
Use the tail command with a special argument. For example, to skip the first line of a file:
$ tail +2 lines
An argument to tail, which is a number starting dash (-), will specify a line offset relative to the end of the file.
So tail -10 file shows the last 10 lines of file, which also happens to be the default if you don’t specify anything.
But a number starting with a plus (+) sign is an offset relative to the top of the file.
Thus, tail +1 file gives you the entire file, the same as cat. +2 skips the first line, and so on.