There's no one size fits all fertilizer. It's dependent on your soil and water.
You can have soil or leaf analysis done, or use other means of determining what is needed.
Where I am, soils are dry for most of the growing season and pH tends to climb, so adding things like sulfur and gypsum greatly benefits most of the fruit trees in the orchard, as well as a source of potassium (sandy soils leach most of this during the rainy season). There tends to be enough plant residues to supply nitogen and the soil is not deficient in phosphorous.
Depending on your situation, you may have much amending to do or none. What kind of soil do you have and what is the typical rain situation throughout the year?