Kin

1. UNCLE BEN'S DEATH

I believe this one is pretty much obvious since it literally happens in every adaptations of Peter Parker and recently in the animation, with Miles Morales and his own uncle.

It is explained that Uncle Ben's death (or the death of an uncle i. e. Aaron) is crucial for every Spider-Man to learn that their actions have consequences and that they should take responsibility of it whatever happens (okay that did not make sense but you get it!)

But of course it can be different, just like for Gwen because Peter died for her instead of you know, an uncle.

2. CAPTAIN STACY'S DEATH

This one has been shown multiple times in the films and how it clearly affects both Gwen and Miles since both of their dads are/going to be captains.

The death of the "captain" is what causes the divergence of the couple (like with Gwen and Peter from the TASM, but I don't remember the movie much to vouch for this information) but it doesn't mean it's the only effect that could happen. But I think, the "Spider-Man" has to have an active role for this happen or to be considered a canon event, just like for Pavitr and Captain Singh, to which it almost caused a drastic, tragic event for him and Gayathiri.

For Gwen, she was worried about this canon event given that her own father is the captain and the fact that it's a canon event that he dies (which makes two canon events happen at the same time for her but I'll elaborate this one later on). But we all know he quitted and that changed something soooo

And for Miles, he's trying to save his father because he's going to be captain and that he'll die (which can be considered three canon events happening but idk)

3. PARENTS DYING

This happens everytime, duh. I mean, Peter Parker always grows up in the care uncle Ben and aunt May because his parents died.

For Gwen and Miles, they're yet to experience this canon event.

As I mentioned, Gwen will experience two canon events happening at the same time if her father died. One, a "captain" dying and a "parent" dying.

As for Miles, he'll experience three. One, a "captain" dying, a "parent" dying, and this could affect his relationship towards Gwen (which is not possible on Gwen's side, considering that Miles did not meet her dad, but she did) + (Gwen could possibly have an active role in the death of his father if it was to happen)

4. BEING BITTEN BY THE RADIOACTIVE SPIDER

Of course, how can you be Spider-Man without being bitten by the spider? It's the same old tale for every characters that turns into a spider persona— they have to be bitten by the spider.

The conflict that was delivered in the movie happens because Miles was bitten by a spider that was meant for Earth-42 Miles Morales; and yes, there should not be two Spider-Man in the same universe as implied. But of course, it's not also expected in the first movie for Peter Parker to die but someone has to take the mantle of Spider-Man (I'll explain this too, I guess)

5. EVERY UNIVERSE HAS TO HAVE A SPIDER-MAN

This is obvious because as what we've seen there's literally Spider-Man for each and every univeres, regardless of their genders, powers, nationalities, races, and etc...

A universe without a Spider-Man is dark and destructive, just like in Earth-42 to which Spider-Man never existed because the spider was not there and has not bitten the Miles there, ceasing the possibility of the Spider-Man persona to exist there.

Hence why, Peter's death in Miles's universe is considered an "anomaly" because Peter Parker already existed and he's already Spider-Man, but with the spider biting Miles (and said spider coming from another universe that is supposed to bite the Miles there), and the death of the former Spider-Man, it is a canon event that someone has to be Spider-Man.

BONUS: GWEN STACY FALLING IN LOVE WITH SPIDER-MAN

I think this is just more of Gwen's speculation as she travels to different timelines and all, but we know it's because somehow Gwen always ends up in a tragic death or traumatic stuff with her relationship with a Spider-Man.

I don't really see it as much of a canon event, but maybe it could be, given that Gwen dies regardless if it's in the comics or movies.