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This is a request that has been made many times here. A Search for words like Learn and Tutorial and Books and Training will reveal more threads than you will ever want to look through, with book titles, links to websites and videos, etc., etc.
My favorite goto AutoLISP book: AutoCAD Expert's Visual LISP
please provide link to download for free
If free is what you want, the link below will be your best bet. AutoLISP/VisualLisp has not changed much since the book was written in 2000 -- just 'vla' introduction/changin/removal of functions that coincide with the VBA API functions are the only things that have changed over the years.
Thank you