Sorry if I've caused alarm and despondency. For most people there should be no problem, and for the majority of people who use their ISP's DNS services it's certainly true to say that the ISP is responsible for ensuring that their service conforms to the new standard.
But I always think that it's better to be prepared. If you happen to be one of the unlucky few who experience problems after the changeover, you may not even have a usable internet connection to enable you to search for a solution.
Here's another way of checking, which you may find easier to use and understand. Download
DNS Benchmark and run it. You don't have to install this program, just run the executable which you downloaded. It's a Windows program, but it also works perfectly in Linux using Wine. When it's running, click the 'Nameserver' tab, then right-click in the middle part of the window; a popup menu appears, and you should click on 'Test DNSSEC Authentication'. Then click the 'Run Benchmark' button and leave it to work, which takes several minutes. A progress bar at the top lets you know how it's progressing.
When it finishes, click on the 'Conclusions' tab for a report.
(Apologies to SS44 for repeating things he already said )