Like most others have posted, you won't go wrong with a .30-06.
I started with a .30-06, and many deer, elk, and antelope fell to that rifle. I shot 150 gr bullets for deer and antelope, and 180 gr bullets for elk and moose.
The first scope that I put on that rifle was a cheap Tasco, which I later "upgraded" to a 3-9x Weaver which I used on that rifle for over 30 years, for dozens of elk, deer, antelope, moose, and caribou.
I now have Leupold scopes on most of my rifles.