For the majority of his life his relationship to his dad was pretty okay. They went on a lot of activities together he spent time at his house etc etc but after the divorce (as stated here already) he became irritated with his parents and Lanza‘s Dad noticed he was becoming disinterested in him.
September 2010 they went to look at a college for him together and Adam insisted on taking 5 courses, while his dad was sure that it would be better if he took only 2, as to not overwhelm himself. This angered him so much that he refused to see his dad the following weekend and then completely cut off contact until he died. Sometime in spring 2012 they agreed for a meeting, but it didn’t happen.
I don’t think he ever outright stated his opinion on his dad, but I’m sure he was irritated and angry with him for underestimating him and since they never got to reconcile, I guess it’s your way of interpreting his feelings on him.
Though his dad DID say that he believed Adam would’ve killed him too, had he had the chance.
(For more understanding you could read Peter Lanza‘s Interview for the New Yorker!!)