Habitat for Humanity.
Read their book. The entire book. Reread the electrical several times.
Then, donate a few weekends to Habitat helping to build a house.
You'll learn more on site in a month than you will in years staring at a screen.
Some areas have incentives for improving the insulation.
To get an idea what is inside a home.
Home depot etc home improvement /repair books.
Check home yearly, keep up with repairs.
Water, termite damages fast. Roof , check and replace when too old. Don't delay this.
Afci/gfci ac plugs to replace old ones that aren't smart to increase safety.
Range hood vent. Clean the filter, check 3-4x per year. Grease = potential fires.
A couple of fire extinguishers mounted throughout. Fire alarm in every room.
Check furnace filter and change 4x+ per year.
Any water valves that leak, replace. 1/4 turn ball valves more reliable.
Water heater past 5 years? You'll have up to about 5-8 years more before it breaks.