I've got some bare ground that I don't want to have to tend to in great details & am not that fussy about plants. I've worked out I need "ground cover" but how does it work?? Do weeds not just grow in between the plants? What if there are bulbs or dormant plants underneath - will they grow through when it's their season? And if the plants aren't evergreen won't it just look a mess in the winter with nothing there or plants with bare twigs?
Plants compete for resources like light and nutrients, so where there are already established things growing that you like, you are less likely to get weeds. This does not mean you get no weeds at all - it just helps to keep them down and give you a hand with keeping on top of everything.
Most kinds of ground cover plant will grow with bulbs, though bear in mind that the same competition will be going on. (Most spring bulbs are so packed full of energy that they will punch through a lot of other plants, though even they have their limits). Most other plants are the same, though I wouldn't necessarily put something very delicate with a very competitive ground cover plant.