Airbrush brush?

The main ingredient of a Photoshop airbrush preset is to have Build Up checked.  This causes the brush to continue laying down 'paint' for so long as you have the mouse button pressed, or stylus in contact with tablet.

You need to start with low opacity for this to make sense of this, but if you are using a tablet, set Opacity Jitter to Pen Pressure

To access the airbrush c.p. showed, select the brush tool and right click inside the document window.

Click on the little cog icon top right corner, and load the Legacy Brushes

It's helpful to have all of the options I have highlighted turn on, and essential to at least have the Search Bar enabled.

With the Lewgacy brushes in the main brush panel, start typing AIR into the search bar.

These are the droids presets you are looking for.

Also there are »airbrush« Brush Tips with further settings (Spatter, …). 

When you have the Brush tool selected click the little drop-down arrow next to the brush size icon on the upper tool bar. The drop-down menu has settings for the brush size and hardness. Those settings alone can give you a very airbrush-like brush, especially if you're using a pressure sensitive graphics tablet. There are folders below containing a variety of brush presets, including some that are similar to an airbrush. The tiny gear icon at the right will open the Brush Settings palette to provide more advanced settings.

Hi @NadiaSon You can use any brush along with the airbrush setting to simulate airbrushing in Photoshop:

https://helpx.adobe.com/photoshop/using/creating-modifying-brushes.html

This tutorial gives a good explanation on how to adjust brush tips:

https://www.photoshopessentials.com/basics/photoshop-brushes/brush-dynamics/shape-dynamics/