My neck started popping/crackling when I turn my head left or right. It does not hurt. Any concerns or suggestions? Thanks

Not really. Many people have non-symptomatic neck popping and cracking (including myself!). You are probably sensing the normal motion of the cervical facet joints. I do not recommend purposeful cracking of one's neck, which usually requires a significant rotational movement of the neck (i have had patients with acute cervical herniations after those maneuvers).