"I need a micro answer, not a macro one."

If you feel you need One on One support, you need to find someone to work with you directly. This is a text-based forum of Peer users on the internet, not Live Chat with QB support or training.

I pretty much showed Micro-details.

"I enter each new job as a new customer"

You can do that, when the Project or Job is not for an existing customer; is that what you are describing?

"and code each expense and income item by that job code."

One item can be BOTH an expense and an income, and that is what I showed. Then, you are Job Tracking = assigning that where you list it, this Purchase is specifically for that customer name, and as Billable or not.

This is seen in Help, as you see in my new attachment. Open Help and search on Work With Items; search on Job Cost Tracking; search on Billable.

And in the video tutorials that used to be in the program:

Desktop PC program video tutorials

"So I have actual numbers by job, but have no budget numbers."

Again, in QB, you find a Budget tool and an Estimate function. They are Different. Budget is "company financials as fiscal year" and Estimates are "Job project scope" related.

You also see this in the Sample file. From the No Company Open screen, bottom Right, use the big Button for Sample Files and open "product-based" which is Rock Castle Construction to get a file that has real data for your to use, learn from, and even Input and see what happens, as if this is your own Real data file.

"I have a budget, created when I bid the job.  How and where do I enter the budget numbers so I can create a report to compare actual to budget?"

Again, you can use Estimate, which is Item Based. Or, Budget, which is Account based And Limited to each fiscal year, not the lifecycle of a Project.