So, I created a second account to have a dedicated breeding account as this is kinda just a junk drawer. I had to leave before choosing starter horses, and now I don't have the option to. Where on that account can I create them?

From the FAQ:

I Didn't Receive My Starter Horses. How Do I Get Them? If your account is less than 2 weeks old and you skipped making your Starter horses, there is a link to them on your Stable Page in the Top Box.

ahh thank you!!! I forgot about the FAQ and now I feel dumb >>;