Got it? You want your garden or your containers to look great, so quite simply learning from those with more experience is the very best way to go. Also, it is not a great idea to take an example of a plant that's doing well in the ground and put it in a pot, as many plants do not do well in containers. Though of course you can ask at the garden center whether a certain plant will do well in a pot, and give it a try, though stay away from things like most trees, unless you have a huge pot.
Oh, and one more little tip, take photos of the plants that you like and either look them up online by giving details of the plant, like "purple daisey-like flowers" and then take a look at all the images the search provides, or better yet, take your photos with you to the garden center and ask what they are.
As for the photo, I took this a month or so ago at a Moroccan warehouse of sorts, and just loved how the flowers looked with the mosaic fountains, but more importantly, I was reminded that I absolutely must give African Daisies (right) a try this year, as they're perennials here and I've seen them also at my neighbors house doing great and not only flowering a good part of the year, but also once again reflowering this year.
Good luck with your adventures in gardening or container gardening, it's such a pleasure to add some greenery to any outdoor space, and flowers, well, they provide a simple joy that one shouldn't miss!