What would you do if you were me? Career change

My husband is a fire fighter and I am an administrative assistant at a public school.

My dad owns a very successful (multi million dolllar) roofing and siding company. My dad is 61 and has health complications and is looking for someone to take over the company. My husband and I want to do it together but we’re both scared to make a career change. We both have pensions, insurance and job security. We are both in a union too.

I don’t have any knowledge in roofing/siding so that also really scares me , however I would mainly do the office work.

What would you do if you were us?