I shaved my vaginal area and now my outer lips are swollen, plus I have a pimple on it. This has never happened what do I do!!

Folliculitis? Almost certainly you have folliculitis, i.e. hair follicle inflammation or infection triggered by shaving. Pubic area folluculitis is far more frequent in the past decade, since genital shaving became common. Wash with soap and water and keep the area dry, and get care if you develop multiple pimples or particularly large ones, or if not better in a few days. And no shaving the next 2-3 weeks.
Warm baths/compress. The pimple is most likely related to an ingrown hair, which occurs often after shaving close or infected hair follicle. Warm compresses usually will bring this to a head or point, at which time it may drain. If the labia is very swollen and painful, have your doctor check it out. It isn't clear why both are swollen, other than minor trauma from shaving or sensitivity to the shaving cream.
Localized reaction. The tissue near/of your genitals has a different sensitivity than some of your other skin. Any agent you used as a shaving aid (cream,oil, soap) may have triggered a local reaction. The scented materials are more likely to do so than scent free. If so, just keeping the area clean and free from trauma for a few days should see improvement. If not, have it checked out. If so, avoid what you used.