I mostly see the word "commemorate" used for people or events in the past. To me it makes most sense in the context of something historical, recurring or continuous.
Can you also commemorate something new, like the opening of a hospital? So, not commemorating the opening of a hospital that took place 100 years ago, but next Sunday we will commemorate the opening of the hospital?
Can I have a party to commemorate my raise or my new car?
Or is there another word that would make more sense in this context?