My dad was covid vaccinated. he had no side effects at all. can this mean i won't have any side effects since we share dna and he wasn't affected? or does it still vary with each individual no matter what?

It varies with the individual. Your life experiences along with the half of each parents DNA you share are the basics for your immune reactions. Most have little if any reaction beyond a sore upper arm.

Response may be variable between family members.

You only share half of your gene with your father. Get the vaccine without worrying about the minor side effects you may or may not get.

For vaccinations, in general, men seem to have fewer side effect than women. When it gets down to the individual, reactions to medications and vaccinations are harder to predict. Most patients, including myself, have a sore arm for a day or two and mild if any other symptoms. Others can feel fatigued or like they have the illness.