Hello there and thank you for using Ask Extension. 

We have quite a bit of information on growing apple trees in your backyard.  I'm assuming that you are focused on  preventing the pests, so I will address that question.  If you want additional information on such topics as pruning, fertilizing, and pollination requirements, let me know.  

Here's some general information on growing apple trees.  There are additional links to articles at the bottom of this sheet. https://planttalk.colostate.edu/topics/fruits/1201-apples/

This next fact sheet is more detailed than the previous Plant Talk article.  It goes into all the details about insects and diseases of apples.  Just so you know, apples are considered a "pome" fruit.  Stone fruits are things like peaches and plums.  Here is the fact sheet.  https://extension.colostate.edu/topic-areas/yard-garden/backyard-orchard-apples-and-pears-2-800/

At any rate, you have written just in time because some of these preventative pesticides should be applied at the end of March.  Let me know if you have further questions.  

Good luck.