Tips for a beautiful garden?

Hi guys,
our house has a very large terrace with twice as much garden area. In the middle of the garden stands a large stone fountain, around it there is only grass. Now my parents wanted to try doing something with all the open space. But they can’t really get started because they lack ideas... I need a few suggestions on how to nicely design a very neat/symmetrically arranged garden.

I agree: informing oneself through gardening books and magazines and recognizing one's taste preferences. Then there is also the time investment to consider, so thinking about whether one has time to care for shrubs. Gardening books are available on every topic: small gardens, low-maintenance gardens, Japanese gardens, playful gardens, flower gardens, shade gardens, geometric gardens, garden courtyards, English gardens, play gardens.... It all also depends on the dear wallet