How does a micro interpret high freq rf signals from an antenna
It doesn't. There are other dedicated circuits that process (amplify and demodulate/digitize) the signal from the antenna, and the results are presented to the CPU at a rate that it can handle.

There are some chips that have this RF circuitry integrated onto the same die as the CPU. For example, in the ESP32 block diagram, the CPU is in the orange block in the center, while the RF circuitry is in the purple box in the upper left. There are additional dedicated circuits in the top center that perform further processing of the baseband signals before the CPU gets them.