My 2 cents.
Having a good centerfire hunting rifle to shoot is one chapter.
Learning the fundementals of shooting is another chapter.
A person who selects the 30-06 for his long term hunting rifle has made one of the finest choices possible.If you want a 30-06,buy a 30-06,and do not let anyone talk you out of it.No matter what cartridge they recomend,it might fit their preference better,but ,while a .270 or a 308 or a 7-08 or a .270 are all great choices,they are not better than a 30-06.Just different.
Now,about that other chapter,learning marksmanship.The 30-06 is not so good.It coists a lot to shoot,so you wont shoot so much.More important,its about developing muscle memories and good habits and techniques,the fundementals.What will set you back,or ultimately make you a mediocre marksman,is buiklding a foundation of bad habits.A few characteristics of a substantial rifle are noise and recoil.I am not calling you a wimp.You may like noise and recoil.Noise and recoil cover up bad habit,actually encourage them.
So,get your 30-06.
But also get a fairly large ,heavy bolt action 22.If you can find an old 1950's target rifle with a fat barrel,buy it.
With that,you will learn your 30-06.And,later,if you want an AR,go for it,but get a 5,56/223,
Its like a set of golf clubs.