Evidently, you do not have the experience, knowledge, or maturity to even begin to consider breeding! Likewise, it is clear that you would like to have a litter purely for the experience, which is extremely selfish!
Furthermore, a 'good' breeder would not allow you to purchase one of their animals if they knew of your intentions!
However, if you do decide to breed, please ensure that you have the contact details of, and means to travel to a cavy savvy veterinarian, regardless of the time of day, or night, and that you have adequate finances to afford any veterinary fees you may incur - If you decide to breed, as other members of the forum have continually reiterated, there is a good possibility that you will experience costly consequences, and potentially fatal complications (Sows often experience complications during, and after pregnancy/labour)!
Personally, I would recommend that you adopt two guinea pigs from a rescue, either a pair of females, or a neutered male/female combination - Males can live quite happily together, but it is not uncommon for males to have issues at some point, and I would be concerned that you would not be able to handle this behaviour, should it occur!