Hi Mike, welcome. DT does not work quite like Lightroom so I can appreciate the confusion. Hopefully I can help ease this a bit:
DT does not move the images for you, so I always move the images to their final destination first before importing. There is a move option in DT but I find it a bit cumbersome so rarely use it. Some people will then use DT to weed out the images they do not want after import, others, myself included, weed out the unwanted images using other software first before using DT.
when you select import, the "image" option allows a manual selection of one or more images to import. The "Folder" option will import all images in that folder without the need to select them individually. If you have folders within Folders, remember to select the "import directories recursively" option on the import screen. So at a guess, you will always want the "folder" option
If you want to move/remove/delete an image. Select the image (on windows this is left click an the use of ctrl or shift to select multiples) then on the right hand side of the screen is an tab titled "selected image(s)" pick this and you will see the options available for the selection. Remove will remove from DT library only. Trash will remove and physically delete the image, plus other options
Each time you import, DT creates a "film roll". This is a fall back to the old days when people had a roll of film so each import is a sort of film strip. Personally I do not use this, but some find it useful I guess. However, look on the left hand side of the screen, there is a drop down tab titled "collect images". pick this, the sub tab you can now see is (probably) titled "film roll". Use the drop down arrow to change this to "Folder" and you can now browse your image collection folder by folder. Pity this is not the default.
You will notice there are a lot of options, including tags for browsing/searching. and you can have selections within selections, it is quite powerful and similar to Lightroom collections. If you want to use Tags, there are discussions on this site about various methods.
So now you can import and find your images easily, the next step is to edit one. When you double click an image it takes you into the darkroom, here you do all your editing.
First and most important, you cannot do any damage to your images, everything you do is stored into an image sidecar (separate file with same file name as image with .xmp suffix, so steve.raw will have a sidecar called steve.raw.xmp. So you can edit away to your hearts content.
Screwed up the edit? no problem, look on the left of the screen and see the history stack tab. pick an entry earlier in the stack and continue from there or go back to the beginning of the stack. Or use the duplication tab to create a duplicate to work on two options. Lots you can do
I wont go into edits, there are a lot of modules and whatever you want to do, there will probably be several different ways to do it and a myriad of people telling you that you are doing it wrong and you should do it their way. They are wrong, the best way to edit for you is your way, and you will learn and refine as you go along until you get that "look" that you want, not what others tell you. However I will just give you a little pointer to help as the edits themselves will seem rather daunting
Under the histogram is a set of icons, click these and they show the modules added to the icon group. Click them again and you get a larger group, yes there are a lot!. at the foot of this tab is another option "more modules" yes there are even more modules!
But dont despair, you will find that for your "style" you will eventually only have a subset that you use all the time. These can be stored under the star icon or saved as pre-sets.
But to help you on your way, DT has given you some general purpose module collections. Look on left hand side of the "more modules" line and pick the 4 horizontal lines icon. This will give you a set of modules pre-sets for specific tasks. Pick one that is closes to what you want to do and start from there. Remember one learns from ones mistakes, so dive in and start screwing up those images! lol, soon they will start to look good.
Finally there are a lot of videos on Youtube. Bruce Williams is going through modules one by one and has around 50 videos so far so worth a watch, and there are lots of others out there.
Good luck and shout of anything is unclear