I have untreated class 1 malocclusion. what's going to happen as the disease progresses and when will it progress?

Bad bites : A class i maloclussion means that your bite on the sides lines up correctly. So you have a good bite with crowded teeth most likely. Teeth that are straight are easier to keep clean. If your teeth are crowded then you may be more prone to periodontal disease which can eventually lead to tooth loss. The best defense as with any disease is prevention just like diabetes.

Keep them clean: I would not consider class 1 malocclusion a disease. Our distant ancestors did not have braces and no one ever died from crooked teeth. The biggest problem with malocclusion is keeping the teeth and gums clean around the crowding. You must get a dental cleaning every 6 months to keep teeth and periodontia healthy around the crowding. If you maintain oral hygiene you shouldn't have any problems.

Not a disease: A malocclusion as a malrelationship of the teeth and/or jaws, not a disease. If left untreated we often see premature aging (wear), compromised bone/gum support with mobility, and sometimes even jaw joint (TMJ) malfunction. Damage is usually a geometric, rather than an arithmatic, progression, increasing with age. Why not see an orthodontic specialist to find out the paths open to you?

Not a disease: But your bite can continue to worsen. I would visit an orthodontist.