Well for starters, no apology is needed, we all have been pests at times and starting off is more of a pain for you (confession: that those of us who take delight in pretending that we're smart just because we have a little more familiarity with the software
The button called 'videos' should really be called 'file mode', and it will access all your files regardless. So naturally anything you throw in sources will be there and the player "thank you devs", will play them. In your case, it's likely that most have yet to be scraped into your library.
I don't know what TMM stands for... The Movie Madness? anyway, as a new user stick exclusively with Kodi for everything. Stay away from programs that pretend to be simple, do a better job etc... some do offer advantages, but it's not for the novice without knowledgeable guidance, run bareback. The biggest issue by a far margin is nomenclature or the proper naming of your files (date) which is very important with multiple movies having the same name.
Let's take 'Flash Gordon (1936)' as an example...(without the quotes, and yes quotes screw up the scraper along with dots, hyphen, and weird chr$ ) using the 'video' button locate the source (hopefully you have set a scraper for the source like the universal scarper) for the folder 'Flash Gordon (1936)' (it's wise to have your movies in a folder of the same name) and hit information ("i" on the keyboard) or scan for new content. You should see something onscreen (perhaps a choice) and follow along; at this point you would have this listing in your library. Exit, and go back to the main home page, a simple search should confirm you have indeed added this to your library (if it doesn't show then it's not in your library and make another post). This would be tiresome if you had to do all of your videos this way; so let's go back to the easy way. Enter the file mode (video button) and locate your source folder, and using the context menu change content, change scrapers 'save', on exit you will be presented with a requester to scan 'all' ... This should start to scrape in all your movies. If all this is a bit confusing, I'll point at the links in my signature along with
Video library (wiki) and
Video management (wiki)