First time pumping?

I'm a FTM, baby is 4 weeks (don't tell me about the 6 week mark I need to start pumping for mental health reasons and will be talking to my midwife about pumping) I want to start pumping, I have a haakaa milk collector and just bought a manual medela pump. I just don't know what I'm doing and I don't really want to create a massive oversupply or cause mastitis.

1) how often should I be pumping to create bottles for partner to feed? I'm still going to breastfeed at home, just would like some for going out or at night.

2) do I need to pump in replacement of feeding?

3) when is the best time to pump? How long??

4) Should I use the haakaa or medela pump?

5) any tips or advice or experiences that will help??