Beginner Gardener, need help with flower bed
So I know nothing about gardening and I would like to know what I should do, start to finish in front of my house. There's two sort of "beds" that could be fixed up on either side of the sidewalk (see image) and they seem to be filled with pebbles and sand and wood chip mulch. It looks awful and I just want to know what I can do to the soil and what kind of plants I can plant to make it look better. I would like it to be reasonably cheap since it's a rental home and I wont be living here forever.
Let me know what I can do!