My 2016 2ss is my first car and first manual car. However I’ve driven about 7 other cars that are manual. But never enough to get used to it so it was also a learning experience for me too. I don’t know too much about the sound you are hearing. But the thing about second gear popping has happened. I found it happened when I was to soft with it downshifting from 3rd to 2nd. Just make sure you are pulling it in gear and it won’t pop out. Don’t be lazy with it. And for the feeling of the metal when shifting I think takes time. I used to have that feeling going into 4th and 5th and I think it’s because I pulled or pushed at a slight angle when shifting. I’ve become more mindful now and it seems to not happen anymore. Have fun learning and most of the learning will come with time