I do not know the age of your son, but most students who are taking foreign language class are in middle school or high school. That is old enough for them to be able to talk to their classmates and find out about what homework they have. If other students knew that homework had been assigned, why didn't your child? If your son doesn't want to ask other students, it seems like your son should be talking to the teacher now (even if it is still the substitute), and find out what he didn't do.
If your son is really struggling in the Spanish class, when you meet with the teacher on Oct.12, perhaps you can find out if there is a way for your son to get tutoring, but from what you are telling us, the problem is NOT the teacher or exactly which 45 things your son didn't turn in, it is WHY your son didn't do the homework, and your son has to tell you that.

well that can be a good answer but the teacher call me {she said was sick} and stated was around 45 projects and the suppose appointment I have with her next October 12 is about the same...
is about look and check some of the words , essay's, questions..but 45 what..I don't want be ugly to ask, I want to know how can be the best way to ask her curriculum...
I want be open and just have the good way without threats but I want to receive a least one answer about how she works...

When my son's foreign language teacher was sick, and they saw movies, the movies were usually young children's films, but in the foreign language.
The students sometimes had homework to identify a couple of foreign words from the movie that they hadn't previously heard, and look up the definitions in the dictionary. Sometimes their homework was to write a few sentences about the movie, like a summary of what the movie was about, or a movie review, explaining if they liked it or not.
Does your son have any friends in the class, so he can ask them what the homework assignments are supposed to be, if he can not understand what is required when the substitute tells them?

nope the teacher is out the school she been sick for more of 2 weeks , and she send me a email my son is never bring her homework, when I ask my son who is teaching them new language {he only speak English} and suppose to get {Spanish class} well our son explain us with a movie the substitute tried to give the class for 2 weeks..so what type of homework students can do with a movie per day :)?

We would like to help you, but need to be sure we understand your situation. Are you asking how to contact a teacher who is no longer at a school, why she failed your child? Or are you saying that the teacher failed your child because your child was out of school when she was sick?
In most schools, the teachers must leave student records for the subsequent instructors to be able to know about the children. This is especially true if a teacher gets sick and leaves in the middle of the year, but even if it was a teacher who failed your child last year, there should be some records that move from grade to grade, so a new instructor has background information. (For example, if a child was struggling in reading, a new teacher would have notes and maybe test examples left by a former teacher, so they didn't place the student in the wrong reading group.)
Have you tried to ask your child's current teacher if there are any indications of why your daughter failed before? If that teacher doesn't know, then I recommend you contact the school principal, who might be able to give you additional information, and may be able to call the old teacher if needbe.