1st - Start shooting good Sub-MOA at 100 yards.
2nd - Move to 300 yards.
3rd - Move to 600 yards if you rifle can do it. If it can't get a precision stock bed it and maybe replace the barrel.
Then continue 100 yards at a time till you get to 1000 yards.
There is more to shooting 1000 yards then pointing a shooting. Its a lot of practice, precision loading, time twecking your gun, etc. The 300 wby is a good one and the vanguard is a good gun so with some work and effort you can get there.