Where to start in recovery

I just bought 40 acres in ID, zone6. For the past somany decades, it has been a tim hay field. The farmer who planted it used all sorts of chemicals. It is a large rolling hill with a small pond in the NW corner.
(Basically a square plot)
The well is up at the top of the hill, only 3 GPM. We are putting in a large cisterne
(buried) and our house is on the south slope, an earth bermed house with the south face out and the rest buried under 2.5ft dirt.
Our plans are to raise a few cattle (3 or 4), pigs, a flock of chickens and some ducks. I am also interested in putting in a fruit orchard (trois) and hoping to do silvopasture with the animals. The main question is how to best help the land to recover from all the previous practices. Where do I start?

This site details rehabilitation techniques.
https://enva.com/case-studies/contaminated-soil-treatment-methods

Some photos would help understanding your layout.
A word of caution, if its chemically damaged groundwater may also be polluted.
I encourage rainfall collection, have you thought of it?
What are your soil types, will fruit trees grow?
What is the local climate?
What is growing in your local area?
How will you water trees?

From Wiki
"Silvopasture (silva is forest in Latin) is the practice of integrating trees, forage, and the grazing of domesticated animals in a mutually beneficial way."

How do I best breaksown agricultural toxins on my site? Given time mushrooms will break down most of those unwanted chemicals. So give your site lots of woodchip, straw, compost and starter mushroom (oyster mushroom, wine cap, etc).

My other thought is to be aware of your limited resources and don't take on too much all at once. Personally I would focus on:
A) a quarter acre homesite, with my kitchen garden (root crops, vegetables, herbs, etc), chicken coop, bee hive, etc
B) a perimeter of (200) fruit trees around the zone listed above
C) a perimeter of woodlot trees around the "orchard" listed above. It can easily be pollard/etc to make firewood.
D) the fish pond, biological filtration for the pond can be done by throwing bags of mushroom-innoculated hay into the pond.
E) the silvo-pasture, same as the other areas, I would just add alot of woodchip/soil carbon.

Karen, welcome to the forum!

S Bengi has given you a great suggestion with the woodchip, straw, compost, and starter mushroom (oyster mushroom, wine cap, etc).

Mushrooms are one of the best chemical remediations there is.

Here are some threads that might help you or others:

https://permies.com/t/107880/Interesting-quick-fixes-work

https://permies.com/t/118870/soil-recovery-spring

https://permies.com/t/188976/building-fungal-soil

Yes, we have thought about harvesting rainwater. While our house will be underground. We are planning a workshop and barn both with metal roofs for rainwater harvesting ability. We will have a large filtering system for the house but hope to use rainwater for animals, gardens, etc.