Probably need some details as to where this property is.
I have well and septic, have had it for over 10 years.
Well, once a year i dump some liquid pool chlorine down it.
I run a water softener on it that i cycle once a week for my use.
Other than that, just check your pressure tank, when it stops maintaining air pressure and you have to keep topping it back up, replace it.
Eventually the pump needs replaced, not actually a terrible job, you could pay a well service, they pop out and do the job in a couple hours, or with a few tools you can do it.
Septic
Where i live the septics are above ground, raised mound type, not that it matters much.
So i have a pump for it (lift station) because the tanks are higher than the house plumbing.
The pump is a cast iron grinder pump, they last a very very long time.
And they are user replaceable easily (If you can work in a box of shit water that is)
Most people do not have lift stations so house just feeds into the septic.
Have it pumped out and filter cleaned at least every 2 years, solid waste does not magically go away.
Only water soluble goes away, solid sinks to the bottom, fatty stuff floats to the top.
Pumping it out takes away the stuff that isnt going to go away.
I do not put any kind of stuff they advertise into the septic tank, i have been told they tend to do more harm than good.
Build your septic leach field bigger than you need, a field that is always saturated is not good, it tends to grow slime which clogs the leach tubes.
I’d recommend you keep a good layer of earth over the access hatches on the tank.
The tanks breath, when yucky water goes in, yucky air comes out, no dirt to act as filter and you get a nice aroma.
(No it isnt as terrible as it sounds, but sometimes people keep all the dirt off the top to find the caps easier, and then the thing farts into the open air all the time)
Be mindful of what you stick down the septic, since it does not magically go away
NO DIAPERS NO TAMPONS NO KOTEX!!!
Yea i know people flush that stuff on city sewer systems, DO NOT put it in your septic!
No cigarette butts either.
Dont use acid toilet cleaner, dont use drano, they tend to be unfriendly to the bacteria breaking down the stuff the septic system can make go away.
Poo Pee shower sink etc water.
Dont user a garbage disposal on the sink, it’s too much temptation to overload the septic with solid waste it does not need.
Consider using a grey water recycling system for laundry and bath water, It’s free lawn watering and reduces the load on the leach field a ton.
If you are buying a pre existing set up, have it inspected by someone YOU paid, not someone the seller paid.
Buying a house with a bad septic is not exactly a NO, but it is a hey you reduce this price by $28,000 or no sale type thing, cause you will spend that redoing it.
If you area is prone to power outages, consider a small little generator so you can run the well pump if you have an extended power outage, the well does not need much.