Most new carpets shed. This is normal and should not be a concern. Even if it sheds what you would consider a lot, it's likely still normal, especially for a carpet with a heavy, dense pile. The shed fibers that you see are usually just a small portion of those in the carpet, and unless your carpet is a defect, the shedding should stop, and your carpet be just as plush and dense as it was on the first day it was installed.
Use a vacuum with adequate suction and a roller brush or adjustable height feature for the pile type of your carpet. The best way to improve the suction of the vacuum you currently own is to check the bag frequently and replace it as needed. If you own a bag-less vacuum, dump it frequently. Also take off the bottom carpet attachment on the vacuum cleaner and manually remove as much of the hair, fibers and other debris as you can. Then look at the hose connector and inside the vacuum hose. There may be more hair, fibers and debris stuck in those places, as well, that you can easily pull out to improve the suction.
Vacuum your carpet soon after it's installed and before you put your furniture back in place. This will help remove the initial fibers that may have shed in the first couple of days.
Continue to vacuum on a regular basis. Every day or every other day may be necessary the first couple of weeks. Within a month or two, the shedding should slow down, and within a year, it should cease completely.