Nawaz

go to court were people out side setting in table make oath commissioner invitation letter with passport copy   stamp  smiply cost 500 Rs . 

Pakistan is South Asia not MENA.  
 
As the poster above stated above its pretty straight forward.   You get the rupee stamped paper add your wording and have it attested.   
My first VISA to Pakistan I needed a letter it granted me 1 year single entry visit.  I had to register with authorities upon arrival and was not allowed in the CANT areas.   My second visa I did not need the invitation letter I used my marriage docs instead which granted me a 5 year visa, multiple entry, I do not need to register and have no restrictions. 
 
 

no, it is not please read my posts
what matters is quality of time together and overall quantity
 
 
I had  visits totaling 2 month at the time my husbands visa was issued
we had minimal other red flags

Brother
I encourage you, or better yet your fiance to come read the guides on this site, they are very informative
AS for visa, after you are married your wife will need to file a petition for you. You should be reading the guides for a CR1 visa, as this is the visa you will be hoping for following your marriage.
Expect the overall visa process to take a bit over a year, but be very aware that in Pakistan it is not uncommon to end up in AP (Administrative Processing). Most people do not end up in AP, but it is a possibility. Should you find your case ends up in AP, processing time could be quite a bit longer.
 
 
 

not necessarily
I got married on my first visit, and filed directly after
 
culturally it is not necessarily normal in pakistan to meet multiple times before marriage
 
Editing to say, I believe this is very strongly worded and a bit incorrect for Pakistan
 
It is not normal to have several visits before marriage

Please be aware that it will take more than one visit to get approved for a spousal visa.  Make sure that before your future wife files the I-130 petition, that you spend lots of time together, multiple trips, and document everything.  Wouldn't it make sense to meet multiple times before deciding whether or not to get married?  Marriage is a big step to make that decision without even meeting in person one time.  Also coming from Pakistan your marriage relationship will be scrutinized very closely so you will need much evidence of multiple visits to be together in person, evidence of co-mingling of finances, to show an ongoing, bona fide marriage relationship.  If you do not do this BEFORE submitting the I-130, your chances of getting a visa are very slim.  Take more time for multiple visits before getting married and filing the I-130 spousal visa petition.  And study the guides yourself, and your future wife needs to study all of the guides since she will be filing the petition and at a later stage, making a financial commitment to support you if she has sufficient income to do so, if not a co-sponsor will be needed.  And DO NOT get married on the first visit because it will look like fraud.  Good luck!

There is no visa that allows you to go back with her. 
 
After you guys are married you Can Apply for a spouse visa CR-1 visa. It Will take about 12-14 months.