There was a lot of food at the party. (completed action in the past)
Había mucha comida en la fiesta.
There was a lot of food at the party. (action not completed in the past, descriptive)
Which action is (not) completed in the past? The party? What if we add "ayer" at the end of the examples? Will is change anything? Is the process of eating food meant at completed? So "hubo" in the first example means that food was over at the party?
Please help me to understand the differences in these examples. Thank you.