The recommended tire inflation info is usually posted on the inside edge of the driver's door, on a sticker. You do not want to put the tire inflation that is listed on the tire itself, as it is the Max pressures the tires are set by the manufacturer of the tires. Hope this helps.
The safest /best tire pressure is what Nissan recommends. Found in the owners manual or on a sticker, inside the glove box/ door jamb.
The maximum on the tire is the maximum pressure the tire can be safely inflated to in order to carry maximum load the tire is rated to. You car probably weighs less than half of what the tires are rated for, so the tire pressure has to be lower than the maximum, Nissan engineers figured this out for you and gave you the information in the owners manual.
Current trend is to use Nitrogen inside the tires. More dense than regular air so pressures are more stable. But if you check your tires often you will be ok with good old fashioned air. The Tire plackard on the door jamb (some times under the console lid) is cold tire pressure. So add 3 or 4 psi after you drive and the tires warm up. Also there is a owners hand book section 8 page 39 all the way to page 50 continues to tell you about tire grades and DOT numbers and general information about tires. Depending on your car tires size Altima's use 29 to 35 psi cold pressures.