Your iPhone arrived with the USB-C connector on its Lightning cable, and your computer has the older USB-A connector.
USB-C is smaller and is reversible, and can be used for power (including enough power for a full laptop!), USB, Thunderbolt, or other connections, depending on some details.
USB-A is the older and rectangular connections, and the plug only goes into the socket one way.
If your computer has no USB-C ports but does have USB-A ports, then you can acquire a USB-A to Lightning cable from Apple or from various other vendors.
You can charge rapidly with a USB-C charger such as that 20 watt model, or can charge more slowly using a 5, 10, or 12 watt USB-A charger, or with whatever wattage (5W, 10W, or 12W) might be provided via your computer and its USB-A connections.
If you want to use your Mac or Windows computer for iPhone backups or such, you’l need a matching Lightning cable.