No to Trading, as a newbie: most times newbies thinks that trading is quite easy, and they feels they can milk something good out of the market without any knowledge of technical and fundamental analysis, but after some tries and they got burned, they will start saying that trading is a scam, so the best thing is to avoid trading as a newbie.
No trading as a newbie shouldn't be a mistake as then how do you become a professional at trading if you don't start as a newbie, nobody starts trading as a professional, they had to start small, learn and made mistakes that made them who they're. What I think you should say is that newbies shouldn't start trading if they haven't learnt how to trade properly and have done some practice with demo accounts that has no risk or little risk with small money to prevent lost of big capitals. You can't avoid mistakes as a trader as you will have to make them to be capable of learning from your mistakes. Trading isn't gambling and we should not forget about that.