I just got a 6month old boxer

Question
I bought a box of wormer (114mg tablet of pyrantel pamoate/praziquantel) the pamphlet weight chart says she should take one whole tablet but not the frequency of doses it says I should ask a vet for assistance this is purely preventative since she has not had any shots or wormers since her first round near birth she has no signs of having worms but like i said its preventative the brand name of the drug is called Worm X plus and other the weight scale to tell you the dosage she should take it says the consult a vet for assistance in the treatment of this medication

Answer
If you're giving it as a "preventative" you just give one dose on whatever schedule you've chosen.  (Some people give it monthly, some every other month, some every six months, etc.)  It's best to talk with your vet about "preventative" worming, since really there is no such thing.  Wormers don't prevent the dog from getting worms - they simply act on any worms the dog might happen to have at the time.  If the dog doesn't have any worms, there are no reasons for or benefits to giving a wormer (but you do still have all the risks).  A safer option is to have a stool check done, and give a wormer only if worms are found.  (In that case, you generally give a wormer once, and re-check the stool in 2-4 weeks; however this may vary by wormer so follow your vet's directions on that.)