The Unbeatable Squirrel Girl Vol.2 #02
(It's ALSO a great "continuing-on" point for existing readers.)
In this issue, Squirrel Girl gets sent BACK IN TIME and also ERASED FROM HISTORY. Only her friend Nancy even remembers she existed!
So Nancy turns to the only hero she can contact (on social media) for help in rescuing her: IRON MAN.
Also a surprise villain shows up, from the past! It could be LITERALLY ANY BAD GUY but it's a good one, I PROMISE.
P.S.: it is not Galactus; we already did him.