It’s actually not that high-tech… Like jamming a wifi signal is basically like just shouting over someone to prevent them from speaking (or at least from being heard). To make one from scratch, you need a little bit of technical prowess, but it’s definitely a beginner project… But to use one, you literally just turn it on, and maybe choose a frequency. They’re widely available and cheap.
There are pretty cool sophisticated digital crimes out there though, so take heart!