[scorpio45]

I apologise in advance if this question is far too basic or if it's in the wrong place. (If the latter, can a moderator move it to a more appropriate place, please?)
I have a Kindle Paperwhite, and have some 200 books on it at the moment. The books were all sent directly to the Kindle, so I have no file of titles, etc. on my computer. I am a new user of Calibre, two days in fact, and I want to set up a library of the books I have on Kindle. I've scanned the user manual, dipping into sections I think might help, but so far can't find any mention of moving from Kindle to the computer. Clicking on the Add Book button gives me options, but all seem to want files, which I don't have.
Alternatively, I'm happy to manually enter the titles into Calibre, but don't seem to be able to do this either. This would also mean that future purchases would have the same problem if sent directly to my Kindle.
The only thing I can think of is to set up a database or spreadsheet, manually entering titles etc. and saving them as a file, then importing that into the Calibre library, and from there, let Calibre do its thing in regard to metadata, covers, summaries, etc. etc. and anything else it wants to do.
I should add that while not completely computer illiterate, I'm not a computer whiz kid either - quite good in areas I've learned or worked out over time, but not so hot with areas with which I've not had much experience.
Again, I'm sorry if this is really, really basic, but I would appreciate any help anyone can give, and if it can't be done, then so be it.