how do l get ready for the higher altitudes of breckenridge,l dont wanna get sick, l am going snow skiing for my first time in feb and l am 51 and what do l look for if l do get sick from the altitude? signs?

Altitude sickness is a common occurrence when changing the elevation of u body. Lung conditioning, running, swimming & general physical condition is needed. When u arrive at Breckenridge, allow the first day to adjust to the altitude, get a good nights sleep, then ski easily the first day. This should help with the lesser oxygen content.
If this is ur first time skiing, take a package of lessons, including equipment rentals. Many areas offer a ''Learn to Ski Week'' for reasonable rates.
My advice is take a lesson from a professional instructor who u do not know & make new friends, while keeping the old ones.
As to signs of altitude sickness, lightheaded, nausea, in severe cases, vomiting.
Back to conditioning, l use a jump rope, 15 minutes a day to get ready for the season. Also u r younger than I, so u should be able to prepare ur body by Feb. After skiing, ice ur muscles for 20 minutes, then hot tubs or saunas.
Enjoy our sport. Jim.