Brake pad on new bike
Noodle: the metal pipe that turns a V brake inner cable through 90 or 130 degrees to go to the handlebar brake lever.

To disconnect or reconnect the brake's noodle you would squeeze the end of both brake arms inward toward each other.  This presses both brake pads into the rim.
If you can reach, hold them in place with your secondary hand, and use your dominant hand to install or remove the noodle from the flippy arm bit.
 From https://www.chicagobikeblog.com/blog/2014/2/20/how-do-you-get-the-dang-wheel-out
There is not a lot of slack to do this; it should be a close fit.  The rubber boot just slides out of the way, and when you release the brake arms, they will pull themselves away from the rim (allowing the wheel removal.)
Given that you already have something wrong with the brake setup, it may not be able to get the noodle in/out because of the brake pad being mis-positioned.  Or the wheel may not be installed completely right, also blocking things.
If its a brand new bike, most bike shops offer a ~6 week tuneup/service for new bikes sold.  Check with your supplier.  This is one feature missing if you bought the bike on-line.