OK, now it's working. (Had to get the "noscript" settings right so I could do the captcha. I thought that wasn't necessary for logged-in users.)
Anyway: Here's the one I composed yesterday but couldn't post because the changeover was in progress by the time I was done:
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Serious vacuum just means the water is more than 30 feet down. No big deal.
I'd pull everything off/out-of the hypothetical well pipe then lower a weight on a string. Then pull it up and see how far down the water level is. Also how far down the well goes (though you might want to rerun that test after you've cleaned it out.)
You can do a flow test by running an air hose down the pipe and blowing some compressed air down. The bubbles will lift up the water (not too efficiently, which is why you don't want to do this as the normal operating procedure) and you can see how much you can get and what quality it is. (Expect it to be pretty dirty at first.)
A submersible pump is good for a couple hundred feet easy. (You want it near the bottom of the well, because the water level will drop as it's being pumped due to infiltration resistance.)
There are well drillers who specialize in resuscitating old wells. (However, using one will bring the well to the attention of the local water authorities.)
If you own a property with an old well you may find that you have water rights you didn't know about. And you may need to defend them or lose them, depending on where you are and the legal regime in place there. (It varies from state to state within the US, too. And it's a REALLY BIG DEAL legally. Like real estate only more so, because water rights can make the difference between nearly-worthless desert and a bonanza farm or subdivision.)
Curiosity: Where are you at? Is it likely the well was just retired when the city water came in?
Once you get it working you'll want to run it a little every few weeks to clean it out and keep it clean.
Once it's cleaned out and flowing you'll need to sanitize it and to check that it is pulling good water, not some contaminated crud.
Don't be surprised if it's a cistern - a big underground tank to store rain water collected from the roof - though the vacuum argues for a well. (If it IS a cistern there are cute, no-moving-parts-but-the-water, plumbing arrangements to automatically dump the first few gallons of downspout water from each storm, along with the dirt they wash off the roof, then capture the rest.)