I’ve noticed Asana only lets you delete tasks individually rather than in bulk. Ironically enough, if there are more than a handful, that can get tedious quickly.
Please consider a bulk delete action for tasks and a recycle bin to review deleted tasks, rather than searching across the oceans and seas to find them again.
Welcome to the forum, @Jessica_Gonzo! How are you trying to delete tasks? Asana definitely lets you bulk select/delete tasks (click one, shift+click the last one, then use the trash icon on the hovering bar at the bottom of the screen). You can also search for deleted tasks using the advanced search (they get permanently deleted after a month, I believe).