Hi Thoatswold!
Of course! In the future I hope to make a guide, once this beta has gone through the testing phase.
Since you managed to download a TV show, I'm assuming you correctly selected at least one data provider (TVDB, TMDB, TVMaze).
So it sounds like you did everything right, so maybe we should see what the AutoDetect "log" says.
Option 1;
After step 3 you should see the files in the "Selected Files" list.
If you do NOT see anything in that list then something is going wrong.
Something that happened to me during testing: accidentally dropping the wrong files on RMTV (I dropped .nfo and a .jpg file on it - which are not movies).
If notifications is enabled, then a message should have popped up saying how many files were imported.
Now, let's say there are files listed, then you can hover over the file to see the results of the AutoDetect.
And you may be able to see why it went wrong.
Option 2;
Basically the same as Option 1, but now by looking at a longer log (more intended for myself).
Pressing "F3" should bring up the AutoDetect log and there should be messages in there.
If F3 doesn't work, then try to open the "About" menu (if I recall correctly - it's a little different under macOS), there should be an option "Open AutoDetect Log Window".
Let me know if this shows what may be going wrong, or not.
Also: can you let me know what operating system you're running? (just in case I'd like to do some testing here)