Haha..I think you don't need to worry about that too much because most of Koreans are also very confused to use them including me.^^
Here is a thing.
In general, "-예요" is a contraction of "-이에요".(이에=예)
and it will be ok if you just remember this simple rule.
*Pat'chim = 받침
- Nouns without Pat'chim + 예요.
- Nouns with Pat'chim + 이에요.
For example,
제 이름은 우유커플사랑해 예요.
the last word of your name "해" ends without Pat'chim.
제 이름은 파스칼 이예요.
'ㄹ' as in "파스칼" is Pat'chim, but it should be "-이+예요".
(it's an exception for people's names with Pat'chim.^^ - Thanks Hailey..:D)
그는 선생님 이에요.
also there is the Pat'chim 'ㅁ' as in "님"
그는 학생 이에요.
in here Pat'chim 'o' as in "생"
As for '을/를', the same rule applies.
Nouns with Pat'chim + 을
Nouns without Pat'chim + 를
노래+를 하다 to sing, there is no Patchim in "래".
음악+을 듣다 to listen to music, 'ㄱ' is Patchim as in "악".
CD(시디) + 를 사다. no Pat'chim in "디"
소녀시대 + 를 좋아하다. no Pat'chim in "대"
소녀시대 공연 티켓을 사다. Pat'chim "ㅅ" in "켓"
not that difficult, right?
^________^