By default, in a grid visualization, once you mark a task as completed (whether it's "Done", "Won't do", etc), it will disappear from your list. Within kanban visualizations, completed tasks will show since the most recent Monday (i.e. a current work week)
From the View menu, choose whether to always show completed tasks, never show completed tasks, show only tasks completed today, completed since a specific day of the week, or set a custom time frame, like since April 15th, 2020.
Although this is the simplest way of customizing how long you see completed tasks in your list for, you can also create a smartlist with filters like "Completed at" with relative dates or custom dates to achieve a similar result.