Hi fred408,
The easiest way to begin with is this: Make a note of your exact printer model. Then use, for example, Google to search for that model. Very often, one of the first search results will be a link to the printer manufacturer's support page for that printer. However, be careful; make sure that you visit the official web pages of the manufacturer when you are looking for drivers.
For the HP LaserJet Pro MFP M227fdn, one would find this support page:
https://support.hp.com/us-en/drivers/selfservice/hp-laserjet-pro-mfp-m227-series/9365384/model/9365388
Choose the operating system version. Check whether the offered driver/software version can be used.
Also, generally speaking, one could check whether a printer is in the list in About AirPrint - Apple Support as a model supporting the driverless AirPrint technology. In this case, an M227fdw is mentioned (but not the M227fdn). AirPrint does not per se require a printer with built-in Wi-Fi. A network printer, wired to a Wi-Fi router via Ethernet, could also be used for AirPrint, but only if the model supports the technology. When two models are close, it may be worth investigating further. Just as an example, AirPrint is mentioned in connection with both M227fdw and M227fdn in HP's mobile support article (https://support.hp.com/us-en/product/hp-laserjet-pro-mfp-m227-series/9365384/model/9365388/document/c03722645). So, ask HP about whether AirPrint actually can be used with your printer. Alternatively, just test it with an iPhone/iPad connected to the same Wi-Fi router (an AirPrint printer should be selectable when you try to print from the iPhone/iPad).
By the way, AirPrint means that a printer is compatible with macOS, without the need for a separate driver. Drivers/software from a printer manufacturer may or may not add functionality.