how to print attachments in emails

Then you would open an attachment and then press the share button, which should give you a choice to print. Remember the device has to be connected to the same wi-fi network as the printer. Use AirPrint to print from your iPhone, iPad, or iPod touch - Apple Support

Before you are able to print anything from the iPhone or iPad, you must have a printer that supports AirPrint, or an app specific for that printer. From there, you can open an attachment and then you should be able to print it. Documents, pdf, photos are all something that you can print.

That is true. It is going to be dependent on the type of attachment you have. You did not identify anything in particular, so I answered that as clearly as possible, without having to provide precise information for each type of attachment that you could encounter.