Ben would’ve been born in 60 BBY. He also would’ve been Owen’s brother, indicating perhaps that his birth name was “Ben Lars”, with “Obi-Wan Kenobi” being a nom de guerre he adopted upon becoming a Jedi.
Anakin would’ve been born in 55 BBY.
The Clone Wars would’ve ended in 35 BBY. The wars, in part, would’ve been a conflict between the Republic and malevolent Clonemasters, possibly with a Mandalorian clone army at their command. A few decades of peace would’ve separated the wars from the rise of Palpatine’s New Order and the Jedi Purge.
Palpatine wouldn’t have been a Sith. He would’ve been extremely old, having been a senator in the Republic Senate in the pre-Clone Wars years, but would’ve used a combination of dark side sorcery and cloning to extend his life and maintain a youthful appearance.
Yoda would’ve already been living in exile on Dagobah for a hundred years or more, indicating he didn’t participate in the Clone Wars or know Anakin personally.
Luke & Leia’s biological mother may’ve been a Fallanassi adept named Nashira, though this is a VERY unlikely possibility. She wouldn’t have died at the end of the trilogy, whatever the case.
Jedi would’ve been allowed to marry/have kids, at least within their own order.
There would’ve been more lightsaber colour variety, for Jedi and darksiders alike.
Qui-Gon wouldn’t have been Obi-Wan’s primary teacher.

Suffice to say, an EU-accurate PT would’ve been a very different animal to the GPT even if the main beats of the trilogy been preserved.