Create a new catalog and import (ADD) images to Lightroom and then organize them inside Lightroom.
You can rename your images as well.
Like you, I had my share of problems getting started, but a couple of suggestions may help you-
1. To 'start over'- the simplest method is to simply start a new catalog ( and delete the old one later).
Two ways for a new catalog-
a) Hold [ALT] when you start Lightroom and select the option to create a new catalog. or
b) when Lightroom is open, Menu > File > New Catalog.
2. When you first Import images into Lightroom-
a) Select your top-most (master) folder that has you images (eg. Pictures), (Hopefully you keep all your original image files under the one master folder, making backups easier!)
b) Turn on the option to 'Include sub-folders'. (this will import everything in your 'master' folder!)
c) Use the "ADD" option. (which does not move or re-name anything) (Do NOT use 'move' or 'copy'!!!)
Doing this will preserve everything you have done in you computer operating system to your folder structure and image file-names- nothing changes!
Your folders will be visible in the Lightroom Folders panel just as they exist on your hard-drive.
My biggest fear is that your previous attempts to import have upset all your folder names and image locations. This may continue to be a problem that requires manually fixing.
When you become familiar with the detailed working of Lightroom, then you can consider re-naming, moving, etc.
File and Folder "renaming" isn't really necessary for "organizing" your image files inside Lightroom. I highly recommend the below book by Peter Krogh for guidance. It says Lightroom 5, but the suggestions apply to all versions of Lightroom (6, CC 2015):
I just got started with Lightroom 5. First thing I did was to import all photos I had on my computer. (more than 100 000...) Then I realised the names and the dates on my folders were in different formats...some yyymmdd, some dd_mm_yyyy, some yyyy_mm_dd. In addition I had put some into folders like "Summer-07" , "Tour nov-09" etc. Chaos.
I deleted everything from Lightroom, and decided to go through everything and change the names/dates to yyyy_mm_dd. Was this a good or bad idea? Could it have been done in another and easier way?
After this I imported all the photos into Lightroom again. Some seemed to be "remembered" by Lightroom, and were not imported, I had to untick the "don't import suspected duplicats" to be able to see them.
My solution, although some people reject it, is what works for me ... and that is to leave your names and dates unchanged. This gives you the opportunity to create a stronger organization scheme, using keywords and other metadata. If you use the approach of organizing by keywords and other metadata, and searching by keywords and metadata, works regardless of the names of your files and folders ... in fact it will work properly even if your photos and folders have randomly chosen names (although I don't recommend that). And once you create this organization using keywords and other metadata, you do not have CHAOS, even though your file names and folder names haven't changed, you have a powerful and flexible method of finding photos easily. (And if you really want to find photos taken on a specific date, the Lightroom Filter Bar makes thjis simple, again regardless of the actual file and folder names).
And yes, I also highly recommend the book by Peter Krogh
Thanks to all of you for your good advice! And I have bought Peter Kroghs book, it looks like just the right thing for me now!
One more little question: When I start a new catalog and start filling it up, will the tags I have already put on photos in earlier tagging (in the catalog I will delete later) follow them?
will the tags ... follow them?
First answer- No
Second answer- Yes!, if you have firstly saved metadata to you image files in the 'old' catalog. So if you still have the 'old' catalog, open it up, select all photographs, press [CTRL+S] (or Menu > Metadata > Save metadata to file). Then start the 'new' catalog with a fresh Import of your images.
Only some metadata will follow the photos if you do this. Some will not. Specifically, the metadata that doesn't follow is: virtual copies, collections, edit history, pick flags and a few other things that I don't remember right now.
Which again is why I recommend you work on your existing catalog. You will lose nothing. Add keywords and other metadata. Eventually (yes, this is going to take a while) you will have a strong organization with your metadata.