I consider trading as a professional activity. It requires analysis, research and others knowledges. Gambling you just require luck. But yes, maybe there is a thin line between then. It depends on how you do trading.
You are saying all OK but one thing remember if you are doing this without any research and analysis then you are doing worst thing because you have no option for return and you can lost all your money in just few moments as I done few weeks ago 
You are right!!!... There are thousand of trading books, courses and related. At least I think one have to learn how to read japanese candlestick and patterns...and maybe that is not enough