Please confirm if when emptying very old dust, dirt & lint from vacuum cleaner that it can only make a person sick but not anything drastic like eventually turn into cancer. i inhaled a decent amount?

Dust, dirt, and lint are not cancer causing. Unless the vacuum contained carcinogenic debris (like asbestos) which can cause mesothelioma you have no worries.

Household dust is not likely to have adverse effects on your health and no additional risk of cancer. You can reduce your risk of cancer by adopting healthy habits: Eat a mostly vegetarian diet, avoid alcohol, tobacco and street drugs, avoid excessive exposure to sun, get HPV vaccine, exercise 30 minutes each day, drink enough water so your urine is mostly colorless.