You can add a bit of CSS in order to number your list rows. This will number all list rows on your site. You can add specificity to the selectors to target a specific field or form.
/* Numbered List Rows in Gravity Forms */
body .gform_wrapper .gform_fields .gfield_list {
counter-reset: gf-list-counter;
}
body .gform_wrapper .gform_fields .gfield_list .gfield_list_header::before {
width: 1.5em;
content: '';
}
body .gform_wrapper .gform_fields .gfield_list .gfield_list_group::before {
width: 1.5em;
line-height: 2.25;
font-weight: bold;
counter-increment: gf-list-counter;
content: counter(gf-list-counter);
}