Country house purchase questions

I'm looking to move further out into the country but all the houses are on well water, septic or cesspool, and most are oil heat. I've never lived in a house with these systems, it's always been modern city water/sewer, gas/electric heat.

For those of you who have those systems can anyone give me a simple breakdown of what I'm looking at as far as maintenance, cost, headaches, if any? What should be a red flag even before purchasing?

Thanks

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