Can you tell me can i become allergic to something you've never been allergic to before?

Yes: The immune system must "see" the allergen for a period of time and if after some or many exposures (seasons for allergies, eating foods, one or more bee stings), the immune system in individuals prone to develop allergy, there immune system begins to make the allergic IgE antibody. On re-exposure (the next bee sting, the next bite of peanut butter, the next grass pollen season) symptoms occur!