Kawaki will be Boruto’s ally at first but will turn on him and be Boruto’s opponent like shown in the first scene of the anime. Maybe, Kawaki won’t be introduced until Boruto goes Rogue. It is possible that Boruto meets and becomes friends with Kawaki while he’s away from Konohagakure. In my opinion, Boruto and Kawaki have a lot of similar abilities but what those abilities will be I have no clue about that.
The difference between the two will be the morals of Boruto’s parents, and Boruto will eventually inherit the Will Of Fire and use these to avenge his homeland Konohagakure and his family and friends. Now, the question remains what Kawaki means when hs says he will send Boruto to the place he sent Naruto. What mysterious place will that be? Or is Kawaki just telling him that he has really killed Naruto, and Boruto will have the same fate?