Put incremental number before each post in Grid layout

You can add incremental number before each post in Grid layout with this CSS:

/* Show index number before posts */
#pt-cv-view-VIEWID .pt-cv-page {
    counter-reset: listpost;
    padding: 15px;
}
#pt-cv-view-VIEWID .pt-cv-page .pt-cv-content-item:before {
    content: counter(listpost) ". ";
    counter-increment: listpost;
    /* You may remove 2 lines below if it doesn't look good */
    position: absolute;
    margin-left: -15px
}

Please replace VIEWID with ID of your View.

With Content Views Pro, please add above code to Custom CSS field in Content Views >> Settings page.
With Content Views Free, please add above code to file style.css of your active theme.

Best regards,