is autism and ADD (attention deficit disorder) the same in a assesment?

I know they're separate conditions but through doing my own researching since realising I may have autism I also suspect ADD but the conditions are very alike so say if I was to go to an assessment (which seems impossible atm) would I be diagnosed with both as I cannot wait and go through the stress of getting both diagnosed, so in a nutshell would it be a 2 in 1 assessment thanks