squealing on braking, but..., ...new brake rotors & pads Options

[Zimluura]

just got a bunch of work done on my car last week.

new brake pads (carbon ceramic i think), new front rotors, 1 new wheel bearing, 1 new hub assembly, alignment, fluid flush, 2 new front tires.

now, when i brake, and only when the car's speed slows a bit (20mph or lower) i hear a squealing sound. gets much fainter (on inaudible) when i brake more lightly.

any ideas on what's going on??
planning on taking it back to the shop monday, but is it safe to drive this weekend??