This is my first time buying PAs and microphones for my band so I am not completely sure of what i will need. My band has finally finished writing music and wants to start adding vocals. Will I need a PA AND mixer? Or can I just get a PA? or are there vocal amplifiers? Also it has to be at least 3-4 channels/3-4 XLR mic inputs.

Not sure if this will help but my band uses clean and unclean vocals(screaming) but are not completely heavy. Also my price range right now is 200-300 dollars and this will only be for rehearsals. Thanks!