Do I need a general contractor to build a house?

[Gator6x4]

I am recently retired. I have done my own repairs or upgrades in regards to electrical and plumbing over the years.
I can do basic carpentry and have the tools to build anything.
I have project management experience in the manufacturing world.

I recently bought an IRC 0016 book online to review and have house drawings approved with an architect's stamp.

My son recently had a house built and says that he became his own contractor as he went there daily to see the work and got up to speed by asking the builders questions. I know contractors manage more than just overseeing the work but I am wondering if it's necessary.

I know enough about carpentry, electricity, and plumbing but I don't feel I know enough about footers, foundation, and waterproofing (basement) to do this on my own.
The foundation scares me a bit. i know a big box company has a reputation for cutting corners but I don't know the details. I am considering hiring a qualified contractor to oversee this up to the point where the concrete is all poured and is ready for framing.

I can afford it but I will also be twiddling my thumbs watching others do the work if I hire this out.

Hoping others here can give some advice.

Look around in your tool selection. Find your ruler. Put it in a safe place. It will be your best friend and used often. Also a 2’ foot and 4’ foot levels will be needed.

Next visit the building inspectors office in the city or county of residence. Obtain from them the footer specs for a residence of a house of your size. (Hight, width, and depth. ) If planning on a basement bathroom, ask about running sewer pipe, water pipes through the footer inside of conduit. Ask about re-bar or wire mesh in the footers and basement floor.

The main thing is communication. Talk to the sub contractors. Ask the Inspector what requires inspection before you can proceed, move on or cover up.

You will find competent Subs are a good source of information. Also ask subs about workmen comp for themselves and employee. Ask about insurance in the event they do something that damages your neighbors property. Be very very careful of those good price and sorry workmanship people. Have it understood from the start that if they fail to plumb a wall correctly it is on there dime to correct including the cost of materials required to correct the wall.

The most important is who is who is going to drive or position the house foundation corner pins for the residence on the footer base. Nothing like trying to get everything to square up with one wall 29 ‘10” and another 30’ 2”. (If coming off the footer with a brick over block foundation check the foundation for being square after the first layer of blocks are in place. Don’t wait until the facade bricks are laid.