I have spend the last 10 years building a thriving food forest in Southern California. Though we are in a different grow and heat zone than you (10b), I still think you might find some of what I have learned useful.
1. Start with the soil. While starting with the plants that take the longest to grow, it’s better to focus on your soil first. This does depend on how good/bad it is. We have added a lot of compost and mulch to ours.
2. When planning what to grow keep these things in mind: will you and your family actually eat it?, will it grow here? Will you have food all year round, as in what can be stored in a root cellar or grown fresh during winter? Will what I grow give our family the nutrients we need. Do we need a greenhouse or tunnel to extend the season?
3. I grow raspberries, blackberries and many other berries in micro climates around our food forest. Do your research. There are plenty that will grow in zone 8.
So, start with your soil, then add large and small trees and slow growing shrubs. Once you get to berries, mark out zones in your garden where they will be protected. Pay attention to when each berry/fruit will be ready for harvest, and pick varieties that stretch out over many months. One thing you don’t want, is for all of your fruits and vegetables to have the same harvest window. It makes preserving the crops a nightmare, and you will end up buying produce the rest of the year.
Look for dual purpose crops. That is crops that will give you two different crops. For example raspberries and blackberries are grow for both their berries and for the leaves. The leaves taste great and raspberry leaves are good for period cramps. Rooted parsley is a vegetable where the top is a herb and the root a vegetable. With peach trees, you can both harvest the fruits and the sap.
Try and make a circle calendar and write in when you can harvest things. It’s a great visual aid, when making crop decisions.
Good luck with your food forest. Here is a link to my blog
Building a food forest on the edge of the desert