I'm American and I have never been out of the United States. Is it true that if I visit Pakistan for the first time I'll only be able to stay a month? I hope this isn't true. I want to stay longer.
The limit you mentioned is only for the business visa on arrival for US citizens (and along with that many other countries).
The business visa on arrival has quite a bit of regulations behind it.
You may obtain a visa on arrival when traveling on business for a maximum stay of 30 days if you have a local sponsor who will obtain an approval from the immigration authorities at the port of arrival.
You must also hold either a recommendation letter from the Chamber of Commerce and Industries (CC&I) in the US or an invitation letter from a business organization recommended by the organization/association in Pakistan or recommendation letter by Investor Consular of Board of Investment posted at Pakistan missions abroad.
If you don't have all these requirements fulfilled you should apply for a tourist visa before visiting the country wherein the duration isn't exactly mentioned on the Pakistan Embassy website, but it would likely depend on your plan when visiting there.
Either way, if you need more than 30 days, apply for a visa before you travel and you can get it.