I would say perhaps change the idea of trying to "replace" alcohol with something else and looking for something that gives you a similar experience or similar motivation. We addicts often trade one extreme with another and that does not resolve it.
I engage in activities that are tied to subject areas I am interested in and also like to find company via those. I think it's so easy these days to explore things given the accessibility of information and possibilities for trying things. For me, one major source is related to my work/career that I love and some of it I can do also on my own at home (need to do a lot of writing, for example), whenever. Reading books and articles. I love learning new things: take classes, go to museums, read up on whatever piques my interest. Art is a major one, too. Movies. Many people love some form of exercise. The mere act of developing healthy routines and habits. Starting and executing new projects. Simply working on practical chores and things that need to be done can also be rewarding.
Also, many people experience depression while drinking and in early sobriety - if you feel that's an issue for you (and might underlie lack of motivation), it may be a good idea to seek help for it. That reminds me, I did a lot of psychotherapy for ~2.5 years in sobriety. I found that very stimulating and engaging, far beyond the direct interactions with the therapist. I also love to have stimulating conversations with interesting people, either just for the sake of it or while doing some activities together.
I do think it's important to find activities in sobriety that are pleasurable rather than just doing what needs to be done but there really are no limits as to what these might be except not engaging.