First off welcome to the family! You didn't necessarily say you're a first time "gun owner" but you're a first time handgun owner and decided on the P10C instead of going with what I like to refer to as the Honda Civic of the handgun world aka the Glock... So congrats to you.
I can't speak from experience on the barrel swap but everything I've read says it should drop right in, I'm sure others with experience can offer more information on this.
As for replacement sights, in your case I'd recommend a night fision set. I like a high visibility front and subdued rear so I kept the stock rear sights on my P10C and lightly painted over the dots and went with a Night fision front sight.
Th photos show my sight setup. The factory rear sights are photoluminescent but the night fision is tritium.