The cream should be stored in the fridge in a sealed container. Take it out 1 hour before using to allow it to soften.
Butter cream is out of favour in modern patisseries, for one thing it's full of calories, and these days the taste is for less rich foods. But also, I fear, beacause it is so easy for a poor baker (whether industrial or not) to make a bad butter cream by mixing margarine with sugar and artifical flavouring. This awful cream eventually put customers off all the good butter creams, which is a shame, as I know people who would give anything for a decent real butter cream with praline for example.