Flowers bring such beauty to a yard, i.e., color, butterflies, etc. Growing them can be challenging and a lot of work depending on what flowers you want to grow. I like it easy; so I will give you easy advice.
Annuals are plants like Impatiens and Petunias that you have to plant every year. It is fun to grow them, BUT you have to plant them every year. (Although I have had both of the above reseed themselves, but they were in pots.) I am lazy and do plant some annuals, but I prefer things that grow back every year.
If you want flowers without a lot of work, I suggest bulbs or perennials - they come back every year for a long time. Everyone knows about Tulips, for example, - a wonderful bulb, but they do not grow in some areas and the bulb goes deeper every year (so they really should be dug up and replanted every so often). Do I need to tell you that I do not plant tulips? Daffodils are great, they come up every spring, and they come in so many varieties.
A TIP FOR DAFFODILS: Once daffodils bloom you must not cut down the foliage. It must be allowed to die back completely. This is how the daffodil bulb gets energy to bloom the next year. I suggest that you tie the dying foliage together so that when the yard is mowed (as many want to do in the early spring), the foliage can be avoided, and the daffodil plants can store for next year.
A great perennial for summer is the Lily. All lilies are not all Tiger Lilies (orange). You can get almost any color you want now, and they multiply each year so you have more and more. They can border your garden or I have seen a beautiful garden that consisted of all colors of Lilies and nothing else.
A wonderful plant for fall is the Mum - again comes in all colors. Mums start sprouting green in the spring and continue to grow into late summer and maybe even bloom then. Want to know how to make them rounded like the landscapers do? It is easy. Just start clipping the green shoots back a small bit regularly in the spring. Each time you clip a stem, it becomes two stems. This gives you more blooms. Also, shaping the plant when you clip gives the rounded look. Leave the top stems a little longer than the sides, trying to make a round look. When they bloom in all their glory, they will not fall over but hold their little blooms high and, if you have shaped, in a beautiful full mound.
IDEAS FOR A PATIO GARDEN
When you do not have a yard any longer and have only a patio you still can have a "garden." There are many plants that can be grown in pots, and garden centers are full of them - single plants or a whole block of them.
You can plant annuals, but perennials can work, too. Annuals, like Vinca, marigolds, petunias, impatiens, coleus, and many others will decorate your patio all summer. Ferns love patios and will keep growing and multiplying into beautiful large plants. A Yucca tree and similar plants love the patio. As far as vegetables go - tomatoes, cucumbers, eggplants, squash, etc. can all be planted in pots. Some will need a trellis to climb if your patio is not large enough for the vines to spread.
You do not have to spend a lot on stands, either. There are many alternatives to actual stands - large flower pots, colorful crates, an old table you might have, or even plastic shelves. Your patio can be a wonderful "garden" just for you.
MY PATIO GARDEN (2018)
I am happy to say my patio garden is doing really well, so far. I face East and the rising sun is quite hot, so I lean a large patio umbrella on the fence to block that morning sun, early when the sun rises. When the sun is high in the sky, I lower the umbrella so my plants get plenty of indirect light.
I have quite a few annuals for summer (with plans for a couple of herbs). Last winter, we had a falling of temps that killed my herbs. I have Oregano going strong right now and plan to add Rosemary and Thyme. I love getting a sprig to add to my cooking. Last year I stuffed my Thanksgiving turkey with my own spices!
I realize the joy of your patio garden might not equal that of a real garden, but, being older, I am in an apartment now. This is the Best I can do and I am enjoying it now.