Brand-new trial version user.  I’m trying to follow the VisualGDB ‘blue pill’ tutorial, and it looks like there were some steps missing for a first-time user

1. The text says “Although we can use a stand-alone ST-Link programmer, in this tutorial we will use the one embedded into a STM32 Nucleo board”  I just have a ST-LINK V2 device, so I want to use that instead.  There is a 5th (red) wire from the Nucleo board to the blue pill reset pin, which is apparently required to implement ‘connect under reset’, but nothing is said about exactly what that does.  Other tutorials seem to indicate that this wire is not needed, so I’m confused.  Does this wire simply force the reset line high or low, or does it do something else?
2. When I get to the ‘Debug Method’ page of the New Arduino Project wizard, it is completely blank, except for a ‘Debug using:’ drop-down list box.  Using this box I can select ‘USB Devices’ or ‘Debug Methods’.  Which do I select?  Also, if I select ‘USB Devices’ and then ‘ST-LINK V2, I get a pop-up dialog asking if I want to download and install OCD.  I learned elsewhere that OCD is a tool for reading and decoding binary files, so I suspect the answer is ‘YES’ but I’d like to get some confirmation before I proceed.

TIA,

Frank