Have mild facial acne scars and occasional acne breakouts. is growing beard a bad idea for my scars or acne in any way?

A beard covers acne: If you prefer a beard, it can disguise the skin problem, but it doesn't change its severity. See your doctor for effective treatment.

Not a problem: A beard can disguise some acne scars. It will not promote the development of acne nor aggravate acne that is already present. If you like the appearance of the beard, then go ahead.