I've been thinking a lot about beginnings lately as I'm at the beginning of Henry Tilney's Diary. In modern novels writers are often advised to begin the book at a moment of change and I thought about where Jane Austen's novels begin.
Pride and Prejudice - begins when Bingley and Darcy move to the area.
Sense and Sensibility - begins when Mr Dashwood dies.
Persuasion - begins when Wentworth returns to the area after a long absence
Mansfield Park - begins when Fanny arrives at Mansfield Park
Emma - begins with Mrs Weston's marriage
Northanger Abbey - begins with Catherine going to Bath.
In other words, they all start at a moment of change.
This is probably another reason why the books seem so modern and are still enjoyed today.