Need help for beginner choosing proper codec for editing

I am a beginner student learning to use adobe. I have most of my experience using small clips, in mp4 h.264 codec (I learned that today). I bought a new workstation that has some powerful hardware but I still have some lag, the computer manufacturers told me to change my codec for editing rather than using h.264 out of my camera and it will run really smooth. I need some help with a basic workflow of each step I should do to upload my files and how to save them, how to change the codec from h.264 to something to edit with, and then how to render this out into a h.264 final video file again. Of course if my list is not the best choice please let me know what steps I should take: I am a beginner and need simple help. 

thank you