Scope of work training courses


I have about 3 years roofing sales experience under my belt but have never learned scope of work while i was with that company. I was strictly sales. I just started my own roofing company and everything I’ve done to this point was to legally get the business started. I’m wanting to do it the right way instead of just jumping into it. My question is i’m looking for some training courses dealing with estimating and scope of work. Needing recommendations from someone in this field of work that’s why i’m on here. Please keep the negative comments to yourself we all have to start somewhere. thanks in advance!