Plants won't thrive without the correct amount of sunlight. Full sun plants will need at least six hours of sunlight, (marigolds and petunias); partial shade plants up to four hours, (impatiens and violas). Full shade plants (begonias and coleus) will bloom without direct sun.
Some shade plants don't bloom like your ferns but they are going to need a lot of shade, if they get too much sun the fronds will burn and you will have to cut them off. A good garden accessory for ferns would be an inexpensive umbrella if you think they are getting too much sun.
To prep your soil rake out debris, and turn the dirt with compost or slow-release fertilizer pellets. Read the plant tag for the placement of the plants - a foot apart might look silly with seedlings, but they'll grow. Before planting just pat the top of the cube and tickle the bottom to release the roots. Stagger plants as you go along; a straight line of flowers doesn't look as natural. Once everything is planted soak it all down.
For seedlings, water is like mother's milk. Hose the bed daily for the first month, even if you put down mulch. Then use the finger test: poke a digit into the earth; if it feels dry it needs water. Same goes if the leaves or flowers look wilted, it is virtually impossible to overwater outdoor annuals. Don't forget to pick up your gardening supplies such as a good watering can, your seeds, a good rake, a pruner, pesticides, and don't forget your gardening soil and
all the plants that you are going to use.
Encourage more buds by pinching off dying flowers right below the blossom; this is called deadheading, before they have a chance to go to seed. For stalks too tough to break cleanly, use a pruner, as ragged edges invite disease.
