iOS/iPadOS doesn’t natively support direct connection to a USB Printer. Instead, these devices use a network connection to supported printers typically over WiFi - or if explicitly supported by the printer, a wired ethernet connection.
See:
Apple AirPrint is a driverless connection protocol. A high proportion of modern printers intended for Home, SoHo and Business environments now support AirPrint:
About AirPrint - Apple Support
If your Printer does not support AirPrint, WiFi Direct is simple wireless alternative - but will require use of an appropriate App supplied by the Printer Manufacturer (e.g., many HP Printers use the HP Smart App).
A further alternative is to add AirPrint support to your existing USB Printer using a Print Server (e.g., Lantronix xPrintServer - or a Raspberry Pi running CUPS). Both are viable, however, you may find that purchase of a cheap AirPrint-capable printer may be more cost effective.
You should note that unlike many computer Operating Systems with which you may be familiar, iOS/iPadOS does have any facility to independently add device-driver software for external hardware devices. The only method by which third-party drivers can be added to an iOS/iPadOS devices is to install a manufacturer-provided companion App.