Will be meeting friends here and touring the museum, then heading back to Copenhagen. Are there lockers at the train station to safely leave luggage while we’re at the museum?
No - not as far as I can see on DSB site.
But Louisiana does: https://louisiana.dk/en/plan-your-visit/practical-info-accessibility/.
But I cannot figure out how large they are.
I don't think so, Humlebæk is a small station with basically just two platforms on each side of the tracks. The old station building has been turned into a café.
Will you have anything with you that you can't leave in Copenhagen?
Thank you for replies. The meet up includes someone coming from elsewhere headed to Copenhagen with this as a stop to visit the museum with us. I could reach out to the museum to see what size lockers they might have
Here is the Museum page that tells about the lockers although it doesn't mention the size.
https://louisiana.dk/planlaeg-dit-besog/praktisk-info-hjaelp/
Scroll down the page quite a way to get to the part where it talks about the cloakroom etc. Google automatically translated the page into English for me.
Thank you. I guess I didn’t scroll down far enough. They do comment on a “few” large lockers. FYI you can flip the info to English with a button at the top of their info page