If i've already had a disease and will i have the necessary antibodies to fight it again?

Usually: Many viral infections occur only once and antibodies provide life long immunity. But there are many exceptions, a person who had chicken pox can get herpes zoster which is caused by the same virus. A different strain of the virus can cause recurrence of the disease. Bacterial infections, can recur, e.g., urinary infections, pneumonia etc. Some viruses persist despite immune response, e.g., herpes, .