We split when son was 3, so similar. He’s now 12 and is happy, settled, doing well at school.
The things that matter, in my opinion, are to fulfil your child’s expectations. So if you promise to take him out on a Saturday to soft play or to come and see him on a Tuesday night, stick to it.
Make sure he sees a mum & dad who agree and support each other, and both love him equally, even if you argue behind the scenes.
Be involved when he starts school. Go along to sports day etc. My ex refused to get involved and our son – now aged 12 – still feels let down.
Having separated can be an advantage. The parents of one of my son’s friends were getting a divorce but still in the same house, and the arguing had obviously been discussed in the playground. Son came home one day, gave me a hug and said “you and daddy never argue, do you.”
That was when I knew separating and not arguing in front of him was the right approach, even if I spend a fair amount of time biting my tongue.