losing water, smoking

I have a 05 mercury mariner. I've been constantly having to put antifreeze and
water in it daily. It hasn't ran hot on me any, and I sat on pavement for 30
mins waiting to see for a leak and saw no water no liquid at all so no signs of
a leak. I checked my oil couple days ago and i know it could use an oil change
but it was completely empty i added couple quarts to it to get me over until i
can change it next week but when I was leaving for work crank up car went to
add water into reservoir and saw smoke like white greyish smoke coming from
above the belt it smelt kinda like burnt smell but i cant really tell for sure if its
coming from the belt or not what do i do??? Please help me!