Do they provide actors with easy access to the entire Star Trek catalogue so they can prepare, or is it something the actors have to do on their own?

I don’t think they actually do it this way. But, if I were in charge, I’d build a tool for actors, writers, costumers, prop artists, etc. that allowed them to quickly search through the entire Star Trek catalogue going all the way back to the 60s to find examples of whatever they were looking for. So, you could search for “Klingon” or “Klingon marriage” or “Klingon ship console” and it would pull up relevant clips. Basically imagine something like YouTube, but containing only Star Trek content, and designed to help all the creative people match their stuff to the existing lore, rather than something built for entertainment.