Trouble with Phonemes

I believe I'm going to have some trouble with Phonemes. For example, when we did the small activity in class I had trouble doing my name. I'm worried that I'm not mastering it as well as I should be able to. If I work with children then this is going to be a problem :( Everything else I'm great on. I can explain as well as work with others explaining the material however, phonemes are giving a little trouble :/