Tumblr & adsense

Hi guys
i want to start with Tumblr account but i wanna know if it saves to put Adsense on Tumblr blogs

If yes, which is best but Adsense code directly on Tumblr blogs or drive traffic to my website or both of them

any advices or suggestions??

It's possible and safe, why not. For adding AdSense ad on your tumblr website you won’t find any widget to add it easily (as far as I know). So the alternative way is to add the script code within theme script.
dashboard => account => edit appearance => edit theme => edit HTML