Tasks can be sorted in any view. When in Page View and Card View, there will be a sort function next to the filter search field. The default sort is by Id, and a user can click on the arrow to select another sort field from the dropdown. To change the order of the sort, i.e. from ascending to descending, click on the or arrows.
In the List View, the column titles in the header row may be clicked to sort by that field. The field for the current sort is the one with the or arrow showing. The Assignee column can not be sorted, but the Filter function can be used for this field instead.
Users will need view permissions in the tasks module. Depending on the user's project permission settings, they may be able to view all project tasks or just a subset. Watchers specifically added to the task will be able to view it.