If we consider our solar system to be just one of many systems in the universe, we can estimate the number of planets based on the number of known stars. As of now, astronomers estimate that there are around 100 billion to 200 billion stars in our galaxy, the Milky Way. Many of these stars are believed to have their own planetary systems.
Recent observations from missions like Kepler and TESS have suggested that, on average, there may be at least one planet per star, leading some estimates to suggest that there could be hundreds of billions of planets in our galaxy alone.
If we imagine that our solar system represents just a third of a much larger framework (such as models considering many galaxies), the actual number could reach into the trillions when considering the countless galaxies in the universe.
To summarize, while we can't provide an exact number, estimates suggest there could be at least hundreds of billions of planets in our Milky Way galaxy, and possibly trillions when considering the entire universe.