Currently there are 8 native Standard Prime lenses for Sony A7R IV and 5 of these lenses are autofocus (AF) type.
A7R IV also has a sensor based image stabilization system which means that all of these lenses will be stabilized when used on A7R IV.
Since Sony A7R IV has environmental sealings (Weather Sealing), you may like to couple your camera with one of these 4 Standard Prime lenses with Weather Sealings.