if you get a DSI touchscreen display it will run out-of-the-box, just enable touchscreen plugin.
There are also cheaper SPI touchscreen, but usually they have a resistive touch-panel, not good enough to be used with fingers.
At the moment I’m using a OSOYOO 5 Inch and I’m waiting for a Waveshare 4.3 Inch DSI
https://osoyoo.com/2019/09/20/instruction-for-raspberry-pi-5-dsi-touch-screen/