What does an effective manager look like?

Id like realistic feedback on this one. I'm somewhat retired and work in consulting when i want to, mostly with small business IT operations, like crm and erp setups, website design, payment processing, integrations, automation etc. Ive been approached by a SaaS company to lead their startup dev team. I understand agile/scrum, sprints, and bug analysis but have never led a full on dev team aside from website design, which is very easy. The gig pays well, so im considering it, but want your feedback. What do you look for in a feature development manager? Looking at their current SOPs, they really dont have any, so ill be building the entire thing from the ground up. What are some things a good feature dev manager employes from the day to day? Note: the platform is built, so ill just be managing feature request development.