Well, I'm a British/Gaelic heritage person myself, but I've spent quite a bit of time with a Native woman from central BC, and I'll give you as much on manners as I can think of.

First, I'd say, is generosity, bringing a small gift, perhaps a bit of food, whenever you visit. Or any tangible symbol of respect. Respect is always important, in whatever way it's shown.

I was told at first, to always take my shoes off, but sometimes I forget and I don't think anyone gets too upset about it.

As you said, listening when in doubt, not speaking too much, but I guess that's showing respect, too. There's a time I regret not speaking, but that was because I didn't point out some food that had spilled.

I was taught to get myself a cup of coffee, get food myself if it's set out, not wait to be served. And, of course, to accept whatever is offered.

I've often found that people in the Native homes I visit are more aware of my internal respect, or lack of it, than concerned with specific manners.

And I've been respected for learning my own language, a couple of them, actually, Irish and Scottish Gaelic, plus some Welsh. I may not speak them particularly well, but it shows that I'm honoring my own ancestors and my own indigenous culture.  That matters to them.

Good luck!

Mara