It's a fair enough story.
A little slow and sophomoric, but it'll be fine for practice making a short, especially if you have the four main actors ready to go.
Should be fairly economical, too.
Page 6 has no clear "where they drifted apart" suggestion.
One scene they're walking down the street A-OK.
The next shot there's something clearly wrong.
WTH happened? They just grow apart 10yrs ago in a single season for no real reason?
Otherwise, it's all fine.
Format-wise you'll benefit from referencing:
However, if you're directing and shooting this yourself spec screenplay format doesn't even really matter, but it doesn't hurt to learn a bit at a time.