Architect, from Revit to max

I'm a recent graduate, I use revit in everything and anything, now I want to go into interior design, 3dsmax is needed , I'm trying to learn it from online courses but so many new things am overwhelmed. What are the basics I need for interior design? Any recommendations for a good online course?

I've been using revit for +4 years and still find new things to learn, is it fine if I don't know EVERYTHING in max and still get a job ?