How long can it possibly take, after you catch hiv/aids, until your body gets sick/you get symptoms? can it take up to years? what's the maximum time?

HIV: The time from initiation of infection until deterioration of the immune system to the extent that you develop opportunistic infections can be quite variable, and depends upon many factors. There are some cohorts of patients who go 20+ years without illness and others as short as 5-6 years. If you may have been exposed the best thing is to be tested ASAP because early treatment=improved outcome.