Avril Lavigne and Chad Kroeger
Robb Dipple/Hilton Media Group
04/12/2013 at 10:00 AM EDT
and Chad Kroeger are both musicians, so it only makes sense they'd sing at their wedding
– or not.
"I don't want to feel like I'm working at [it], because I'll be like thinking about how I – Okay, I've got to sing, so I've got to perform," Lavigne, 28, whose engagement was announced
to PEOPLE in August, tells ET Canada
"I think that we'll just kind of play a song that's maybe a song we wrote together as our first dance song, I don't know."
One thing she is
sure of is "getting the dress, the wardrobe, the rings, the location booked and the décor," all of which she says has already been handled.
The "Here's to Never Growing Up" singer, who flaunted her huge, pear-shaped bauble during the interview, says the Nickelback frontman, 38, "doesn't even know everything ... I think when it comes to menu and stuff like that, I'll get his opinion, but I kind of like leading the way and he's just letting me do my thing."
Continues Lavigne, "I think he's happy with the direction it's going in ... I'm glad he's okay with my style because it's a little out there, and he's like, 'Yeah, do it, do your thing, whatever.' He's stoked. We're excited."