Import Old Catalog on Hard Drive to Newly Downloaded LrC

Hi Friends.  I let my LR subscription lapse for a year, but just reupped.  My previous LR photos are on an external hard drive, organized by what used to be my catalog headers.  For example, "travel,," then within travel "montreal," "San Diego," etc.  How do I recreate the catalog structure in the newly downloaded LRC?

Also, while I'm asking the question, how do I do it in LR Cloud?  Many thanks!!