What's the best way to get over an ex, but still be friends ?

It's been a month since me and my boyfriend of a year and a half broke up. He still wants to be friends and I'm not so sure if that's what I want from my side. I'm still into him , he was my first bf. I want to know what's going on in his life and I have him on socials, but sometimes I feel sad seeing certain things. Today I saw he posted a picture of dinner with a girl without showing her face and I felt so hurt on my end. Maybe I'm just assuming. We talk now and then about small things.

What are methods to mind my own business and just focus on myself. I don't know if I need to get to the point of blocking him. Please no sarcastic answers, I'm just in a time of hurting honestly. How does moving on even work. Is it just time ?

Also , we didn't break off on bad terms. He claims he's not a long distance person and wanted to move on. I think we say it's mutual to make it sound better , but really it was him breaking up with me.