Learning construction, carpentry, etc as sweat equity

[Ricardo Valdez]

So I’m a very green newbie in real estate. I’m literally beginning to learn RE jargon and abbreviations. 

Has anyone ever taught themselves to learn construction, carpentry, etc. to use it on a flip? A do-it-yourself renovation? Would I have a great ROI in learning a certain skill related to house renovation?

Also, what is the consensus on buying a house to rent out? Crash coming?