Don't ever get a trolley full if you're on your own, or even if you're not for that matter. It's only a pain in the arse trying to get it all out the car, or else you have to leave some bags in the boot and go back for them.
Far better to only buy what you know you're going to eat in the next day or two. For me, that's usually about pound or two of meat, sometimes potatoes, bit of bacon, couple of dozen eggs, bread, milk, sometimes coffee, muesli, and that's it. You're presumably also going to need a few tins of beans for your kids, but nothing you can't fit in one bag.