What are some of the simplest chiral molecules in biological systems
Don't get hung up on the "left-handed" and "right-handed" designations for amino acids and sugars. Those are just conventions for distinguishing one mirror image (enantiomer) of a chiral molecule from another. It just so happens that based on a particular way of drawing (Fisher projection) amino acids and sugars that it appears that the configurations are "left-handed" or "right-handed."

As for how simple chiral biological molecules get, the simplest ones that I can think of are alanine or lactic acid. I'm not sure what you consider "intelligent", but these are likely to be found in all life (as we know it).