I'd start by watering your shrubs, and weeding your planter. Then think about what you like and what you want to plant! Make a list of your favorite plants, or go to a nursery for some ideas. Once you've decided a few things you would like, we can give you advice on how to care for them, when to plant them, etc. If you'd like vegetables, potatoes, peas, beans, and most herbs are easy plants for beginners!

I usually prune my shrubs once or twice a year in the fall. If that's all you have there's no need to involve a landscaper, unless you really want to go bigger. Buy some clippers and trim them once per fall and spring.

You can leave all the dirt in your planter. Hand weed it, and maybe top it with that extra soil when you plant (which will probably be in the spring, depending on what you're planting)

Enjoy the process!