Meursault conforms by engaging in human relationships (Marie and Raymond) even though he tries to stay as emotionally removed as possible. He also goes to a job every day. This is perhaps his most conformist practice since it occurs every day and serves two main purposes: to benefit a company and to sustain Meursault’s own way of life, which by his standards, is arbitrary. This shows that he is not completely indifferent. He does certain things to continue his way of life. So, he does find some significance even if it is to make arbitrary choices. Melville’s Bartleby had a much greater (and less selfish) degree of scorn for conformity because he refused everything.
So, I think you are correct. On the outside, Meursault goes about his daily life as most people do. Although he is indifferent to his mother’s death, he does the socially accepted thing by attending the funeral. He does not mourn but he goes through the motions that society expects of him.
Interpretations of this novel often point out that Meursault exhibits the Absurd hero through his actions. But this isn’t always the case. It really isn’t until the murder and the trial that Meursault’s outward actions begin to represent his philosophy of Absurdity. In other words, this is when Meursault’s indifference affects his external world. Then the external world threatens his indifferent existence and he is forced to defend and explain himself. His testimony in court and dialogue with the priest are the final examples where he actually shows his nonconformity to the external world.