If you are going to be planting a good sized area it’s sensible to get your HANDS DIRTY & EXAMINE THE SOIL!
Dig a few pits across the site a good spades depth and withdraw a cross section of the soil. The appearance can tell you things. Feel the soil – does it feel gritty, does it feel smooth in which case clay may predominate which is no bad thing but you do not want drainage to be impeded.
What is the rooting into the soil of the vegatation like. Are there earthworms? The more and deeper the better.
In the right hand picture are two soils local to us. Soil left is darker – more organic matter which is good. Soil right has a shallow dark layer before fading into lighter clay dominant soil and when walking across it felt wetter because of the slower drainage.
Taking things a lttle further you can do a ph test for acidity / alkalinity. The ideal soil for fruit trees is slightly on the acid side about 6.5. However do not be too concerned if it varies somewhat from this and is even a little on the alkaline side, all the required nutrients should still be available.
Wide differences however will mean that some or many nutrients may not be available to the plants. The soil will be too acid or too alkaline but this is not usually the case.
Taking things even further you can have a laboratory test the soil for major & minor nutrients, organic matter and more. This will not usually be required but is of interest. However do GET TO KNOW YOUR SOIL!!