It honestly depends on the baby. My daughter didn't want a bottle anymore at 4mths so I tried small amounts of oatmeal but still tried to give her a bottle, and then mushed food around 5 or 6mths.
It really depends on your little one & your doctors opinion. Our pediatrician had my daughter start solids around 9 months but her corrected age would’ve been 6 months. With my son she gave us the go ahead at FIVE months because he was more than ready 🙃
As far as milk though, at 5 months he was probably drinking 5ish ounces every three hours, I think! But he’s a big boy and didn’t wake up to eat through the night. When we started Gerber it was probably 1 oz a day for a bit to get him used to it then 2 oz -2 times a day.
I didn't start giving purees to my daughter until the pediatrician said I could start at 6 months, but we had some choking problems to overcome before that even happened. I'd always double check advice with your pediatrician before doing it!:)