Phonetic symbols will be unfamiliar if you have never been enrolled in a pronunciation course so the first step is identifying the Phonetic alphabet that your professor is using so you can use it in examinations and other school assignments since that is the one that your professor is familiar with and probably it is the one that he or she is going to use to evaluate.
This is the one that my dictionary includes in every single transcription
Let’s assume that your professor is using this Phonetic alphabet which has one example for each one of the sounds , in case that you have to identify what words belong to the different sounds, you have to rely on your professor , other students , your own pronunciation and last but no least your dictionary.
I rely on the accuracy of the dictionaries since it is the one that we have 24/7 to solve our questions. You have to trust on your own pronunciation but if you are not one hundred percent sure , look up the word in your dictionary.
when it comes to preparation for exams, you should practice words provided by your professor while he or she was teaching or the ones found in the textbook that he or she is using , practice as many words as you know and you will get the desired results
If the professor is using another phonetic alphabet , you must make the equivalences between the phonetic symbols that you use and the ones that he or she uses.
Please take five minutes of your time and watch this video clip made By Cambridge English Channel , it helps with the pronunciation of the every phonemic symbol and it has examples