Prior to contact with Europeans did NA First Nations tattoo their bodies?

While traditions varied, tattoos were quite common. French explorer and artist Jacques Moyne provides us with some earlier images of the Timucua in Florida, showing off their elaborate tattoos. John White, one of the colonists to Roanoke, shows the women of the region with tattoos in his water color paintings. The men in the area seem to have preferred body paint to permanent tattoos, a not uncommon gender division. When the so-called "Four Mohawk Kings" (one was a Mahican and they certainly weren't kings) visited London in 1710 on a diplomatic mission, they were painted. While most have tattoos, with the exception of Peter Brant's, they're hard to make out in the linked image. Here's a larger image of Peter Brant and his tattoos (in case you're wondering, Brant has a small bear beside him because he's a member of the Bear Clan; the other two Mohawks also have their clan totem beside them in their paintings as well). Admittedly, these are post-contact, but they are extensions of older traditions.

Going way back, one of the suggested explanations for the Adena tablets (here's one example) is that they're prints for tattoos. There are grooves on the back of the tablets that may have been made while sharpening the tattooing implement against the stone. The design on the front could be stamped onto a person with temporary paint and filled in as appropriate with a tattoo. At least, hypothetically. Hard to tell after some 2000 years.

I'm only looking (very briefly) at the eastern part of the continent. Tattoo traditions were, of course, much more widespread than that but I'll leave it to others who focus on those areas to answer as they will.

Among the natives of NW California, women often wore what were commonly described as 111 tattoos on their chins as shown here. These were common among the Tolowa, Yurok, Hupa and other tribes. Men of the same tribes wore tattoos on their inner arms that were used to measure and determine value of strings of dentalium as is shown here. For more information see Kroeber's Handbook of California Indians, 1970.