Take an incident light reading- and stick with it
Make sure you have a good stong "anchor" in the fore-ground - which will exibit a strong range of tones - as the background fades progressively towards mid grey.
I usualy fit a light yellow filter - there is a suprising amount of blue light in fog.
I second Garys suggestion of a warm coat
As a beginner - stick at this
As you get more experienced you will find an increase in film developing times coupled with a reduced film exposure will help to combat the compressed tonal scale of the image.