Look through all your local news resources for and from the last few months, search for keywords like closed, closing down, shut their doors, bankruptcy, no longer trading, due to be demolished etc etc.
Secondly, do some leg work, have a drive around and look for signs of places no longer active, you can often cross reference those places with your local news. If you can't drive then walk, take a bike, take a train or bus, get a lift etc.
Thirdly, get on Google maps on satellite view, although it won't show up newly empty places it will show up things like disused railway tunnels that can be found by tracing disused tracks across the map, buildings that have been abandoned for a year or two but not seen yet, pumping stations, quarries etc etc.
The hunt for finding somewhere to explore is a major part of the hobby that people often dismiss, the chase and research is quite often more fun than eventually getting there to find its now houses or just a burnt out empty shell not worth photographing.
There's also no shame in going to old places you've found through the search here, it may not be worth updating the forum with a report on it or you may see a different take on somewhere that is worth sharing, either way you've not visited yourself before so your enjoyment will still be the same regardless of how many people have been before you.
The truth of the matter is unless you do a lot of your own private investigations you will never find somewhere no one has been before. After 40 years I've still only been to probably 40-50 virgin places and probably only a handful of those were worth sharing but the fun and excitement of finding those places myself was worth every second.
Lastly, someone that has done all of the above is very unlikely to then give someone else all the details for them to go and simply rock up to take pictures especially (and dont take this the wrong way) someone that only has 10 posts that are all begging for locations.
