Hi,
If you enter one or several prices in the main product, the system displays the main product prices on the listing.
If you don't want that, simply do not set any prices in the main product and only set the prices in the variants. That way, the system will take the prices of the variants automatically.
Regarding the way you want to display the prices (all of them, a range, the smallest, etc), you can edit your products listing menu/module via the menu Display>Content menus/modules and change the "prices display method" option.