Here is a handy chart to size a psu:
It suggests 550w for a 3060.
But, consider what potential graphics upgrades you might buy for the lifetime of the psu.
There is usually only a modest incremental price as you go from 550w to 650w/750w/850w.
A psu will use only the power demanded of it, regardless of the max capability.
It turns out that modern graphics cards can have power spikes well above the nominal power draw.
Do not buy a cheap psu. Look for one with at least a 7 year warranty.
Seasonic focus and corsair RM are good places to start.