You have at least 3 options:

1. As @alex-sh mentioned, you can use the Weight module, add a weight field to the entity, then add that field to your view (you can hide it from being displayed) and sort by it.
2. Use the DraggableViews module, create 1 view in which you set the order of content (use this as a content admin page where you can drag n drop content), and another that displays the order.
3. There's also a Sortableviews module, but I find this less useful and more potential for issues if there are "multiple sortableviews for the same entity type and bundle".