Less than two weeks into his move from Bournemouth, Semenyo scored a second goal in two games as City won the first-leg 2-0 at St James' Park.
He later said, "Tough game today but if we stuck in there we knew we would get chances. I was in the right area to tap it in and we were victorious so I am happy.
"The whole environment here is perfect. Everyone is confident and wanting achieve the best. I have come into that and they helped with my confidence and made me feel welcome. It's been a lot but I have enjoyed it so far. I am picking things up very quickly and enjoying it.
"I am just taking the confidence I had from Bournemouth here and playing with a smile on my face. I am enjoying every moment."
On VAR denying him a second goal before fulltime, Semenyo added: "The second goal should have counted. The referee came and spoke to me and told me what was going on. It is what it is."