Poker tracker question

[ejay]

i am fairly new to this forum so forgive me if this sounds stupid to the rest of you guys. I am currently playing 2/4 on Party and over 12k hands i have a winrate of 1.9bb/100. I have not been using poker tracker. I downloaded it and i used up the free hands. I was wondering about how:

a) is it used? Do you just open it when you start playing?

b)how do you use it while playing? Do you continually look it up while playing?

I have read some of the micro limit stuff and am familiar with what the diffrent stats mean but i would just like to be sure that i am using it right before making a purchase.

thank you in advance,

ejay