Does look like fungus indeed. There's more than likely no reason to worry about. The majority of fungi growing in/on soil are detrivores (they consume dead/dying organic matter) and pose no threat to your plants unless they are known to act as opportunistic parasites when the chance occurs (aka your plants are already dying/stressed). If your soil and thus your plants are healthy that chance is small.
Don't do anything and let nature take its course. They recycle nutrients and make them available for other life so play a major role in ecosystems.