Gmail won't block an IP unless its a known malicious one, and maybe not even then. That said, the login was probably either a rando script parsing an email/password dump, or it was someone who just got their own email wrong and typed yours instead. I wouldn't sweat it too much.
That said, check here-
https://haveibeenpwned.com/ put in your email address and it tells you if that email address is involved in a known breach, and what info was released. Totally free, no BS. It's used by cyber security experts and companies around the globe. Good to check every few months or so IMO.