If your computer does not have a USB-C port - and instead only has the older USB Type-A ports - you simply require a certified USB Type-A to USB-C charging/data cable. These are available from good computer stores - and Apple. Here is one example manufactured by mophie and marketed by Apple:
- mophie USB-A Cable with USB-C Connector (1 m)
https://store.apple.com/xc/product/HN892ZM/A
You should aim to avoid simple plug-adapters - as these do not contain the protective active electronic circuitry intended to protect the iPad from misconnection and potential damage. Certified cables do incorporate the necessary electronics.