"The dog goes towards the cat."
Translation:Il cane va verso il gatto.
You have to use "verso di" when "towards" foregoes a pronoun, like "towards you"="verso di te"; "towards them"="verso di loro". When "towards" comes before an article you have to use only "verso", like "towards the bed"="verso il letto". This phrase could be translated "il cane va incontro al gatto" too.
Depends on the device you're using but I keep notes of all new words on Google Notes as they occur. Also before moving forward, if the usage of a word isn't clear from the DL exercise, look it up on, say, Wiktionary. Or play with it using Google Translate. Obviously all this slows you down the first time round but next time . . .