97' Pontiac over hearting

I have a 97' pontiac sunfire and I was having over hearting issues since I got the car and now my antifreeze is brown which means my oil is leaking into it any time I drive it my gage goes up which means its over heating and the last day I drove it any where I drove even a 2-5 minute distance the gage would go all the way into the yellow so I would pull over and t urn it off and let it cool down but the last time I had it on it made a really weird squeeling noise and felt weird and I havent drove it since my dad I a mechanic and said I need a new water pump but he is not helping me fix it and I want to make sure I am buying the right thing before I spend money if it is not what I need can you help me?