No, you haven’t wasted your money at all.
You can definitely install applications that others have created on your PicoCalc without having to know how to program. E.g. you can play interactive fiction (for instance, classic Infocom games) on your PicoCalc with Unofficial port of Frotz (interactive fiction). That way you can take Zork with you wherever you go. Or you can play around with the demos others have written for the PicoCalc.
However, a lot of the fun of the PicoCalc is tinkering with it, as someone else said. For that, as I suggested, you should install PicoMite/WebMite or MicroPython on your PicoCalc and start familiarizing yourself with it. This is not something that requires a master’s degree or like. You can start simple; there is no need to dive directly into anything fancy. PicoMite/WebMite and MicroPython are pretty much as easy as things get, even though they provide plenty of room (especially in the case of MicroPython) to grow. As you get more experienced, you can branch out more and start exploring more advanced topics.