Upgrade from Drupal 7/ CiviCRM 4.6.38 to Drupal 9 / CiviCRM 5.37.2
If you have a very simple d7 front end with minimum common modules than it won't be difficult to upgrade from d7 &gt;&gt; d8 &gt;&gt; d9.
To Upgrade Civi i would do incremental upgrade i.e

4.6 &gt; 4.7(latest)
4.7 &gt; 5.8(latest)
5.8 &gt; 5.22(latest)
5.22 &gt; 5.37(latest)

Would upgrade Civi first than drupal.