Are you seriously thinking of competing, or competing seriously?
If the first one, then just get out there and shoot a match.
If the second, then get out there and shoot a match!
The courses of fire are a healthy mix of up close targets and precision shots at distance.
the majority of 3 gun events try and cover all aspects of shooting with all 3 guns.
In the US, the targets out at 400 yards might be 12-16 inches in diameter, but engaging them after you just finished sprinting 50 yards, after engaging 20 targets with your shotgun and pistol, with your adrenaline pumping and heart rate elevated is a challenge.
Ideally:
Your rifle should be able to do 2moa or better.
You should be able to shoot an ipsc target with slugs out to 100 meters
And knock over small plates with your pistol at 25 meters.
This is easy if you are just standing and shooting, but when running and gunning its a whole other animal.
I hate winter.
Registering for matches but not wanting to hit the range because it too fricken cold is driving me nuts.