Hello to anyone reading, I currently just started my hunting journey recently thanks to my brother. He owns a savage axis II chambered in a .308. I fell in love with savage after a hunting trip in Texas where I shot that same axis. So I decided to treat myself and bought a Savage High country chambered in 6.5 Creedmoor. I also bought a Vortex scope ( Viper 6.5-20x50 ). Alright so Here comes the questions.

1. Did I overdue the purchases for my first time?
2. What kind of rail system fits on the High country because I've struck out already twice with 2 different picatinny rails to try and mount this scope?
3. What type of rounds should i be looking for in terms of hunting / range shooting?
4. Is there a significant difference in riffles between 308 and 6.5?

Appreciate any help and or advice in the setup of my rifle.