In short, test ride some bikes and see what feels nice.
I went more on the racey side of things even though I mostly commute on it as I like the feel vs something a bit heavier / non racey. It goads you into pushing harder more of the time.
Rim brakes are adequate is the comment above – they’re not adequate in the wet imo and if you have discs on an mtb you will be shocked. I only narrowly avoided a few big accidents where drivers turned across me etc and the margin was too fine. On discs I’ve had similar things and stopped way more comfortably.
On the big tyre thing I find 25’s on my Caad12 are fine – I’ve runnother bikes with 23’s and they are a lot more harsh / seemed prone to more pinch punctures. I considered 28’s but I’m the tyre I want the clearance would have been a bit borderline – but my gp4000’s in 25’s come up close to 28’s in size anywaynin reality.
On gears also try out something with Shimano vs something with Sram. I’d always had Shimano until my last bike which had sram rival with doubletap. Having gone back to Shimano on this bike (just because that’s what it came with) I definitely preferred sram rival. More snappy / I found the single lever for gearchanges better than the gear lever / brake lever combination for shifting on this one.