First dance

How about if after dinner you visit the tables, then before you head back to the head table you meet on the dancefloor and start your first dance?

For us, we are not using a DJ, but rather DIY a playlist, so our plan is to transition our song into the opening of the dance floor. Our first dance song is an acoustic version, so were going to just splice it (we know someone who can help with this) and make everyone get on the dance floor when the original version starts!

We're having our DJ answer to our guests that we're having our first dance.

This day in age do whatever feels right for you and your FH. Not just because "people will not pay attention" Most of your guests will pay attention. They're there for you and your husband.

There's no real "informal" way to do it since the DJ or something will have to announce you. It would be awkward if you just get up and dance without someone acknowledging it. But if you do it after dinner when people are pre-occupied with food in front of them, having conversation, and going to the bar/bathroom, a lot less people will pay attention to it then if you did it right after a grand entrance.