You don't need to use any EQ, unless your ear tells you that the tone of some audio needs to be adjusted. For example, if a drum is too midrangey, you might want to cut (reduce) the mids a little; if a bass is too thin you might want to boost the low frequencies; if a guitar is too bright, you might want to gently reduce the level of the upper midrange and treble, etc..
A parametric EQ is the most flexible, because you can select the exact frequencies you want to EQ (with a graphic EQ you have fixed frequencies you have to work with). You certainly don't need to use more than one EQ on a track -- typically a three or four-band parametric should be all you need.
However, to use an EQ well you have to train your ears to recognize the tonal character in different frequency ranges and learn what the audible effect will be of applying EQ at different frequency bands, and that takes time and practice..