devtrackers.gg
As a general rule, you don't want to sell a Premium ship. There's a process to undergo to recover a sold one (other then buying it a second time), and the credits you gain from selling it won't be life changing.
---
As for learning CV... welcome to a long journey filled with priorities, decision-making, and panic <3 As a CV player you have to ability to go almost anywhere on the map, and yet only be able to do one thing at a time, while being limited by how far your hull is from whichever REALLY IMPORTANT THING is happening at the moment. This leads to a LOT of decisions to be made from moment to moment, and spoilers... it's never easy to pick which decision is the right one.
I have a Compendium that is filled with information about CV Mechanics and Concepts, including tactics and ideas for what to do and when. Still, every battle is a bundle of chaos, so you do the best you can.
For right now, starting at Tier 8 is ROUGH. There's really a learning process for how to move and shoot, and how to understand AA. I'd really recommend picking up a Tier 4 or Tier 6 CV to play in Co-Op for the basics. If Co-Op gets too repetitive, all the Tier 6 Operations accomodate CV play, so it's a themed story of an experience that you can play and practice on. Once you feel you've got a good foundation, THEN try out that Kaga. The AA is nastier, flak is more numberous, the enemy fighters come in larger groups, and in general the gameplay moves faster and faster as you climb in the tiers.
---
I'm going to relink the Compendium, and I encourage you to check out some of the basics videos. CV-101 and the Coaching Session with WOWStarlord are great places to start.