The most crucial and vital thing in gardening is your passion. Gardening is beyond the concept of entertainment (time-pass) or hobby. Your involvement with plants cannot be on a superficial level. They are living beings and just like your family members they need your attention and love more than food and water. You need to understand, respect and appreciate your plants only then can you call yourself a Gardener!!
Once you have passion, rest everything will look very minuscule. You require a space which receives ample of sunlight (at least 3 hours of sunlight in a day). You need to water the plants regularly (daily). And you need to maintain the plants with proper pruning and composting.
An ideal way to start is to buy one single plant and then every month go on adding different plants to your garden. Starting with just one plant gives you a lot of scope to observe the plant. With such a keen observation you are able to learn a lot of things about the plant. After all, gardening is learnt only through observations.
If it is your plant, it is your Baby. You will have to watch over it and enjoy its growing process. Its new leaves, its first bud, the flowering of the bud, the growth of a new stem. Everything counts.