In the main Explorer window you can change the order of the files you see....on the right hand side of your screen is an option called 'Sort Assets By', this lets you change the order by Age, Title and Size. In the public portal a similar option exists and lets you order by Title, Age, Description and File Type.
There is no option in either interface to 'pin' an asset so that it is always at the top but it is something I will feedback to the development team.
I have a paid subscription now to Starter, and I would like to change the order of the cards on my landing page. It seems like whenever I add a card, that becomes the card that displays first. Is there a way to make an alphabetical listing of my cards while also having my Welcome card "stick" in a place where it will always display as the first card?