Get yourself lots of information before you start with gardening. The practical advice you need can be found in special books, these have exact instructions and many pictures that can guide you.
Gardening isn´t as hard as it seems. You can just let your imagination flow and create beautiful balconies or fields full of flowers and vegetables. No matter if you have lots of space or not or if you would like to use container gardening or think about our environment and use organic gardening, indoor or outdoor gardening.
Don´t change the conditions for your plants quickly and let somebody always take care of them even when you are not there.
A good rake and a pair of garden clippers are the most important (and pretty much the cheapest) supplies for good gardening. The flat side of the rake can be used for preparation for planting and the other side for removing rocks from the soil. You can use the clippers for shaping and removing branches.
Plants need good soil, watering and light, one plant needs one thing more than the other but the questions you should get answered before getting started are what, where, when and how to grow them and then there are no more obstructions to great gardening.