Carnauba waxes are often taken as having more shine than synthetic ones, hence many people top off sealants (which are normally synthetic) with carnauba waxes. Even I sometimes top off Meguiar's Sealant with Pinnacle SS II but that is NOT MANDATORY.
Secondly, there's a fine line between sealants and waxes and many waxes are marketed with 'sealant' name and vice versa. If you see more videos you'll understand what I just said. As I said in my first post to you, everybody will have their own say in this, so the deeper you go, the more you'll get confused.
Bottom line is, nothing can really harm your paint seriously, other than a really abrasive compound used with a applicator designed to cut, or a machine. So you can safely decide on a wax / sealant for yourself and learn as you go.