First off I'll explain the behavior of Ryzens.
You came from Intel- throw all assumptions out the window. Ryzens don't work the same way or respond the same way.
At idle, an Intel will chop voltages and speeds to all cores, but all cores remain active. So the entire 5-6% load gets split over 6 cores or so. Meaning any individual core sees extremely little load, and has little consequential temps. Any peaks will be due to the starting of services on any given core, which still isn't much of anything but a small, momentary load.
Ryzen is entirely different. With Ryzen at idle, all cores except 1 are disabled, inactive. So the entire 5-6% load will be on a single preferred core. This being a considerable amount of load higher than any single Intel core, so consequently will run at higher baseline temps. The spikes will be from one or several services starting simultaneously, on that single core. The resultant spike is considerably higher than the 3 or so services starting on Intel, only the highest of which is generally reported.
Intel @ 10-15°C above ambient is normal, with 10-15°C spikes. Ryzen is closer to 20-25°C above ambient normally, with 20-25°C spikes. On average, at stock settings and stock cooler.
Your temps are fine, that specific CPU is rated to run up to 95C and be safe. Ryzens use thermal headroom to boost higher, nothing to worry about. Zen 2 and higher CPUs are effectively designed to redline.
As for the fan noise, set a custom fan curve on your CPU cooler and fans so they don't spin up only after 60C or so. I had to do the same with my 3900X and NH-D15. That way it won't continuously ramp up and down with the Ryzen temp spikes, which again, are normal. As Windows concentrates more background tasks on one core, the temp will spike higher, same as when you wake up sleeping Ryzen cores. They wake up at close to full blast then chill a bit, generating the "high" temps.
