How to calculate random forest algorithm manually?

I wanna ask several questions about Random Forest algorithm.

  1. Is it possible to calculate manually using Random Forest?
  2. If we can calculate manually, can you please teach me how with this data sample i give?
    Assume i want to get price for:
    -Demands: normal
    -Duration: 30min
    -Distance: 2km


  1. Does the result we get from calculate manually will match the one we run with program?

The reason why i ask that questions is because i’m trying to make a pricing system app with Random Forest regression from Sklearn. The app will use that algorithm to calculate price based on several variables. I also want to know about mathematical theory about random forest and how it exactly works, so i can calculate manually and compare the result i get with the result from running the app.

Please help me. I really need to solve it asap.
I will appreciate any help. Thankyou and sorry for my bad English.