Nice to have a 'blank canvas' to begin. I would terrace it with certain species of plants on each tier, which may need some kind of support to stop the soil washing downhill in winter rains. No shrubs or trees.
The existing flat area would make a nice 'patio' to sit on to relax.
Plants at lower prices can be found from friends , Church Flower Festivals, little stalls outside houses in the country, markets etc. Growing from seed at this time of year will provide plants for next year.
Good luck.