What to do when family tries to argue every decision my partner and I make regarding our son

So a little backstory. I am a ftm and my son is almost 2 months old. Both my partner and I have had problems with pretty much my whole family about the decisions we are making regarding our son.

While I was pregnant I decided with the help of my partner thatI wanted to breastfeed our son. I was telling my family and immediately they tried to argue with me asking wht I wanted to breastfeed instead of formula feed. They kept asking about what I was going to do when I had to breastfeed in a public setting. And I told them I would just breastfeed. I don't care where I'm at. If my son needs to eat he will eat.

Then, once he was born, they started to ask when I was going to start feeding him baby food. They say he is already ready to eat baby food (even though he isn't even 2 months) because both me and my little brother as well as all my grandma's kids started eating baby cereal at like 1 month old. Sometimes even sooner. And every time I try to tell them that we are going to wait until we get the okay from his pediatrician, they keep trying to argue with me about it. I have said this multiple time but it never seems to get through.

So I have a question. How do you get nosy family members off your case when it comes to your child? For me, my mom and grandma are the ones who mainly butt heads with me, but the rest do sometimes. I just want them to respect my partners and I's decisions when it comes to our son. And I really don't want to be mean but I will if I am forced to.