If possible get there one day early and just take it easy and drink lot more water than usual. Also take an asprin or two to help you with possible headache.

the thin air tends to dry you out much faster so you need to constantly be drinking water. Stay away from alcohol. If you experience nose bleed the first night or two, this is fairly common so don't panic. And try to get more sleep than usual. Also scale back on your planned exertion from normal as you will not have the same stamina.

How do I know this? Personal experience. I have been living at sea level for more than 30 years now. And every three four years, I go up to places like Snowmass Colo. Altitude there is 8000 feet and goes up. Also visit my family back in Salt Lake City Utah and where they live is up around 6,000 feet elevation.

Try not to worry too much. Take it easy, slow and really enjoy yourself in New Mexico. It's beautiful there.

smilingcat