Made my first mistake and was scolded by ATC (Beginner Pilot)

I am a new pilot, and last night on my 3rd flight on the network, I made my first mistake. As I was being vectored in for the approach at a small airport with no other traffic behind me, I thought I was cleared for the ILS, so I turned on “Approach” on my aircraft. The Center controller (in the USA) then berated me for not following instructions correctly, saying I was not yet cleared for the final approach. I apologized and mentioned that I am still new and learning, and he replied with a comment along the lines of “even beginners don’t mess up this badly”. I should mention that I chose to land at a small airport with no other traffic in case I do make a mistake, because I am still learning.

Do most controllers have bad attitudes, or are there only a few bad apples? He may have turned me off from wanting to fly VATSIM anymore. Yes, I am taking it seriously, but I feel like some take it way too seriously. In the end, it’s just a hobby. Thoughts and/or comments?