A complete new installation like this is definitely exciting, but certainly also time-consuming to plan. We didn't really have to plan much because, due to the old building, many things were already laid out, such as seating areas, a pavilion, carport, various beds, etc. Even mature fruit trees were already standing.
Personally, I would also make sure that you plant predominantly native species that are adapted to the new climate situation. For a large property, big trees would be a must for me, ones that also become very old. Linden, oak, beech, etc. At some point, drinking coffee under them – priceless, and you can't get better, cooling shade. I am also a big fan of partial wild meadows. Little work, good for insects and birds, nice to look at. Hardy, perennial perennials are also great, they require little work. Maybe every few years you have to divide or fertilize them, but basically, they take care of themselves. Everything mixed wild together, then you have blossoms in the garden from March to October, and maybe even in winter with [Christmas roses] for example (Attention, poisonous). The icing on the cake would of course be a large pond that sustains itself through the right planting, but I don't know enough about that. Certainly also a great thing! Of course, you can combine all this with things that make you feel good themselves. Nice seating areas in various locations, maybe also a play meadow and space for a tent for bigger celebrations, so simply a piece of normal lawn. In any case, with a complete new installation, you can plan everything so that it requires little work and still brings a lot of joy and is also very useful for the environment.