Where are my form unique IDs? I need to add them to triggers/conditional splits

Hello. I’m almost ready to pull my hair out, so any help will be very much appreciated.

I’ve got a list going, and I want to set up two different triggers: 

1. one Welcome email series for Discount subscribers
2. one Welcome email series for Non Discount subscribers

If I understood things correctly, my initial trigger is “Subscribes to Mailing List”, then I add a conditional split in my Discount email flow thusly:

1. Properties about someone > Unique ID > equals > (the first discount email ID)
2. Properties about someone > Unique ID > doesn’t equal > (the first non-discount email ID)

I’ll then have to reverse this in my Non Discount email flow, so that those subscribing to my non discount list see the non-discount emails but don’t see the discount ones.

FIRST QUESTION: is what I did above correct?

SECOND QUESTION: where do I find the correct Unique IDs for each email list? I’m assuming it’s the code that appears when I click Edit on my Email #1 for each series, but I’m either going mental or those codes have changed each time I checked on them...