The lake is beautiful. Spend as much time as you can on it. There are various terminals in the area. Argegno or Carate Urio are the ones nearest to Laglio (wedding site). And there are a ton from the actual town of Como.
Known as "the Pearl of Lake Como," Bellagio might enchant you. Roman and I were wondering what came first: this Bellagio or the Bellagio in Las Vegas. We think Italy copied Las Vegas. And we're joking here. Anyway, it really is beautiful and sits at the crossroads of the lake. The gardens and the little town will charm you. Or maybe not. But I think it will.
We'll be near a lake. We understand. Beach, please! So here are some recommendations for beaches in the region.
The last two times we've visited in the region, we've stayed in Menaggio: a quaint town opposite Bellagio and Varenna with a charming square and a pretty waterfront. There's also hiking into the hills and some of the best gelato at La Fabrico del Gelato. Like-I-could-go-there-every-night-and-eat-that-gelato kind of gelato.
If you'd like to spend some time in Switzerland/la Suisse/Schweiz/Svizerra before or after the wedding, Lugano can be just as majestic as Como except it's like super clean and has the inflated Swiss prices to boot. Still, it might be worth your time (if you have time) to enjoy the region. It's not far from Menaggio and the drive can be beautiful.