can new iPad Pro use10w USB power adapter

There should not be damage, but it’ll charge very slowly. You’ll probably need to not be using it when charges. You’ll also need to scrounge a USB-A to USB-C cable, as the cable shipped is usually USB-C to USB-C. Better to scrounge a USB-C charger. A higher-wattage USB-C charger with PD should also work, if there’s one of those around.

Recent models of iPad usually require a Power Adapter rated at 12W (i.e., 2.4A @5V) or greater to reliably charge - although the iPad will charge much faster when using the supplied 20W USB-C Power Adapter.

The 20W Power Adapters support USB PD (Power Delivery) Fast Charging - operating at higher DC voltages - when used with compatible models of iPad.

Using an underpowered 10W Power Adapter (2.0A @5v) will not cause any damage, but will charge the iPad comparatively slowly, if at all.