hi- i feel like this is a dumb question, but i'm a brand-new gardener and don't know where to start!

i have an area of full shade under multiple trees. i would like to plant a ground cover of spotted dead nettle, but i would also like to have a few other perennials too... not sure, but maybe columbine, *maybe* bleeding heart (although i'm not sure how it would like the soil under trees, being dry?), maybe hellebores. i also would like to have some spring-blooming bulbs like grape hyacinths. But, my questions are:

1) If I have a ground cover, will other plants (bulbs, perennial flowers) grow up through it in the spring?

2) Which do I start planting first? Is it too late to even plant anything now in central NY- should I plant the bulbs in fall and wait til next spring to plant anything else? If I plant a ground cover, then can I ever plant anything amongst it ever again? If so, what would I do- just dig up spaces in the midst of it to plant stuff?

3) If I do decide to plant hellebores and columbine, anyone know when I should plant them?

Thanks!