You are right! To be able to change the results format, you need to change the template files. So you will need to copy your template file from wp-content/plugins/sportspress/templates/the-template-you-want-to-change.php
to wp-content/themes/your-child-theme/sportspress/the-template-you-want-to-change.php
and make the appropriate changes.
For example. For the template event-blocks.php
you need to change line 222 from:
<?php echo wp_kses_post( sp_add_link( '<span class="sp-result ' . $event_status . '">' . implode( '</span> - <span class="sp-result">', apply_filters( 'sportspress_event_blocks_team_result_or_time', $results, $event->ID ) ) . '</span>', $permalink, $link_events ) ); ?>
to:
<?php echo wp_kses_post( sp_add_link( '<span class="sp-result ' . $event_status . '">' . implode( '</span> : <span class="sp-result">', apply_filters( 'sportspress_event_blocks_team_result_or_time', $results, $event->ID ) ) . '</span>', $permalink, $link_events ) ); ?>
Thanks,
Savvas