how i can Get the data from the second line

RouterOS General
1

Hello everyone, please help me how to get the data from the second line
Example:
scriptname → data

1234 → first data
5678 → second line data

sample script from first data

:local firstline [:pick $data 0 4];
2

In recent ROS versions there is :deserialize command which can parse text (split it into array) by some separator (delimiter), new line in your case:

:local dataLines [:deserialize $data from=dsv delimiter="\n" options=dsv.plain]
:local firstLine ($dataLines->0)
:local secondLine ($dataLines->1)
...etc