You can only drop your studies and start working full time once your employer has obtained an approved LMIA - and you have applied for and received a closed work permit. Has your employed obtained an approved LMIA yet? The LMIA is the first step.
Don't drop your studies or start working full time until you have completed all of the steps above (i.e. obtained an approved LMIA and then obtained a closed work permit). If you drop your studies and begin working full time without completing these steps - you will be working illegally and in violation of your stay in Canada - and can forget about using that job to apply for PR.