C (like the C in Cenae) could be pronounced Ch, or Ts- depending on where you are from. People whose native language is German tend to pronounce this consonant as TS. Most everyone else pronounces it CH.
In the same way, G is pronounced hard if the native language of the people speaking it is German. It is pronounced soft in most other cases. Sometimes when it is followed by an N, it has a NY sound, and sometimes (more often in Germanic countries) both consonants are pronounced (like it is in the English word “signal”)
Both of the vowel sounds in “coenae”, the “oe” vowel and the “ae” vowels, are similar to short E sounds- but a little more closed (leaning to a long A sound) than the E in “egg”. The sound is actually somewhere in between a long A and a short E sound. (unfortunately I find very few who follow the rule of pronunciation)