My advice (as an older person) is to 'stop reading and start doing'. You will and can learn and get a feel for business by actual transactions with people and in particular directly with them. Where you can observe reactions (ie facial expressions) and by asking questions or offering information/answers. Especially helpful (again from personal and lucrative experience) is when you can observe reactions from some kind of interaction. (In this order: in person, by phone, by email, by text). Each has it's advantages and disadvantages (ie 'in person' less interaction (travel time etc.) but more info gleaned.

This is quite different than traditional 'manage by numbers' or 'do surveys'.