Hey there, 

I did a quick search and couldn't find much about upgrading/updating modules to Drupal 9. I'm sorry if I missed it, please just point me to right direction. 

Long time Drupal user (5.x was my first experiment with Drupal and I've been on Drupal since the early days of 6 - not using Drush - yet ).

I need some guidance about Drupal 8.x modules/themes upgrading to Drupal 9.

I'm ready to move on to Drupal 9 (currently 8.9) but my theme and slider are not compatible (or at least, have not been updated for 9). Suggestions?

I'm thinking about taking a whack at updating the theme and slider module myself - any gotchas I should watch out for)?

Is there a list of which module or theme files need updating from Drupal 8 support to Drupal 9 support? I've seen lists for Drupal 7 to 8 but not 8 to 9.

Or would it be better/easier to look for a Drupal 9 compatible slider and theme - if so, which slider would be best/easiest?

Or should I just wait to upgrade and hope the theme and module are upgraded?

Thanks,

Robin