Just not sure I'm getting it right.

Roxanne • Pregnant with baby 5, due June :)
My little man is 3 days old today, just came out of hospital yesterday night, got very little help from midwifes in hospital (seemed like the annoying person keep buzzing) so put my little man into formula. I still really want to breast feed. I actually don't have a clue where to start. I've expressed this morning... Only managed about 30ml- he took it from a bottle very quickly, then topped up with small amount if formula. how often should I express? His showing no interest in latching on and I'm happy to express. Any tips would be fantastic.