Your situation sounds a lot like mine. I am currently playing a Fey-Touched Gnome Wizard in our Age of Ashes campaign. I read Gnomes of Golarion and tied that in with the additional lore from the Lost Omens Character Guide. I was a little confused of the direction that I wanted to go after reading Gnomes of Golarion, but I think I grabbed a few key elements that I will incorporate as I continue in the adventure.
I think the great thing about Gnomes is that the ancestry represents so much versatility because their lifespan is dictated by one over arching goal and that is to stave off the bleaching. IMO, this means that you can represent the character in many different ways and have them dabble in a multitude of many things. It simply represents their desire to always stay busy, learning new things, and pretty much stay alive. I think playing a Gnome you should always keep that sense of whimsy and curiosity. Whether it's in an obsessive way or in a "Hey look new experience, let's do 'xyz'", is really up to you. If you want to be overbearing at times, I think you can play it up, but in a fun way. For example, I gave a lecture to our Barbarian while I was Treating wounds about the school of conjuration. Since I had to do multiple applications, in game time was probably 30 mins so the GM would cut to instances of me explaining the complexity of conjuration magic. It was great without being disruptive.
I'm already having my fun playing my Gnome Wizard. While he is an illusionist, he's taken the Fey-Touched sorcerer archetype to tap into his bloodline. He's also got a Faerie dragon for a familiar that loves to play pranks and eat chocolate so that adds to the whimsy and unpredictably. Sounds like you're off to a great start with your Gnome! I hope you stave off The Bleaching!