Hi there!
Thanks for reaching out to us.
Are you talking about the SP page Builder, please? Did you mean section by the word "line"?
However, if I assume you want default top,bottom padding value for all of your sections, then there is no default option to change the preset value. But you can use custom CSS, but it will apply to all of your sections with !important priority.
#sp-page-builder .page-content .sppb-section, #sp-page-builder .sppb-section {
padding: 75px 0 !important;
}
Note: Path towards custom CSS(Joomla 4): System>Site Templates Styles> Click on your current default template name then choose Template Options. Then find custom CSS within the custom code.
https://prnt.sc/5mBuSRh907N3
https://prnt.sc/ooiq-lkMEXr_
https://prnt.sc/nunlX-f5AhK1
Best Regards