Certified GKH Gardening Expert
That is completely up to you! If you choose another evergreen conifer type, you probably won't have to amend the soil.
If you choose something that is deciduous, or cannot handle the acidity of the soil then you will want to amend it before planting.
Your local extension service can help you find out what is the condition of your soil: https://www.gardeningknowhow.com/extension-search
Here are some articles that will help you: https://www.gardeningknowhow.com/special/organic/the-importance-of-soil-for-an-organic-garden.htm
Since your location is within zones 7, 8, AND 9 I will recommend plants for these zones: https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-7/planting-gardens-in-zone-7.htm