what he said above
good starting point would be to shoot "Short Nationals" 4doz @ 40yrDs & 2 doz @ 30yrds, once you feel comfortable shooting this round and want that extra challenge go to "National" 4 doz @ 60yrds & 2 doz @ 50yrds, and so on by the time you are shooting comfortably on "Nationals" you`ll probably find yourself achieving 2nd class scores and be ready to go onto long nationals for 1st class (or even bowmen scores for the ladies)