Beginning singer having problems?

I am a beginner in singing, so I am not very knowledgeable. First, I am having a problem clearing my throat. I am not sick, I just have allergies, so do you have any suggestions as to what to do to clear one's voice? Also, do you have any suggestions for vocal warmups to widen my range of singing? I'm having a hard time hitting higher notes and I don't want to damage my voice. Thanks in advance.