I know the biggest factor for me when starting my garden was getting the soil tested and learning what to plants and when. There are tons of free resources online (just type in gardening for beginners and you'll get free ebooks like this to help you start). Personally, I recommend doing a raised bed and filling it with part garden soil and part mushroom soil. I like to do veggies that have a high return like tomatoes, peas, peppers, potatoes and lettuce. Since this is your first garden, buy seedlings (already established baby plants) at the store instead of starting them by seed. When you do plant them outside, you may want to 1) put an umbrella over them to protect them from sun shock if it's already very warm out and 2) put either chopsticks or forks spikes up to protect them from getting eaten (the story of my first garden...) Hope that helps!!