Broadly speaking, the first thing to realize is that almost all First Nations or Native American cultures are far more communally minded than individualistic. To the extent that this is true, questions of sexuality play far less a role than do questions of gender identity, with historic cross-gender or different-gender identities being far more important than any concept of different sexualities.

Within Cree and Metis culture (and yes, I know Metis culture is always post-contact) there are numerous stories, stretching through to the present, of both women who lived the lives of men, hunting, trading, engaging in male activities, and taking care of a family, and also of men who dressed as women. There is also the concept of two-spirited, referring to a mixture of identities, which seems to be more common within the Cree/Anishnaabe communities than mainstream homosexual identities, but I admittedly know less about the history of this, except that it is not a new thing.

In most Pacific Coast nations (and at least the Navajo inland as well), their is the cultural concept of a bardache or hermaphrodite, often involved in creation stories, and apparently it was so common that it merited its own word in Chinook Jargon, a trade language used in the PNW.

The most important thing about how these communal cultures view homosexuality is the way in which community roles (identity?) overshadow questions of orientation that are held so high within a western context. In the community I grew up in, and in the two communities I have lived in since, the majority of homosexual men are married with families, even when they are openly homosexual. And over half of those that I talk to regularly have said that they aspire to the same.

This is not because they are looking to give up on their orientation, but rather that as cultural and knowledge carriers, as people with stories and culture to pass on, as members of the community their desire to pass on what they know to their children is a far stronger part of who they are than is their sexual orientation, and this is something that is a function of the type of society they live in, and this society has this in common with all early Native American cultures.

I'll add as an aside, that at least in Cree and Michif, we do have words for most different types of sexual activity (in fact, when the elders starting spitballing all the different words they'd heard of or could think of, I learned quite a bit myself about what they considered possible). These covered homosexual activity as well as heterosexual. There was however some debate as to whether these were old words or words that had been created more recently. I'm inclined to suspect it was a mixture.