Shooting through the glass can be problematic. The glass is DIRTY. smudges, streaks, black marks from pucks. Depending on auto-focus style you may end up with more pics of the glass in focus than players. I shot rink side for 3 or 4 games and never liked it.
You can get reflections of what’s behind the glass in your photos.
I got high enough in stands so the goalies and the far side of the ice were unobstructed. It limits some shots but you can still get plenty of good ones.
The biggest issue is lighting. In older rinks there can be one or two stops difference between the center ice and the corners. My local AHL rink installed LEDs a few years ago and it is nice.
I shot with a Canon 1D MkIV, 300mm f/2.8 lens, ISO 2000, f/3.2 and 1/1000 shutter.
I’d sing to the heavens for that kind of keeper rate, especially when inexperienced.
My first time shooting volleyball my keeper rate was just below 8%. Because of my inexperience, I did a lot of shotgun pictures.
My first game, I was taking pics for local small newspaper. I was expected to write an article to accompany the photos. After culling the photos, I fired up my writing brain. Then I released I didn’t know how many games were won (best of 3). I dod r know any players names. I didn’t know the final score of any of the games.
BIG learning curve.
Keep practicing and heed the advice given above. You will mess up sometime, we all have.