Wa alaekum us Salam brother.
Yes, if you don't know Arabic then you first need to learn the Surah in order to recite it daily.
Because Quran is not just any ordinary Arabic book, that you can guess from your unconsciousness and keep on reciting. You need to know what Quran is saying and then you can recite it. In Arabic such small mistakes while reciting them can change the entire meaning. If you don't know Arabic, and you recite a verse, you won't feel a difference but in Arabic, just a slight change in the phonetics would totally change the sense of the verse.
Quran has no doubt. As it is stated in the first Surah Baqrah that there is no Doubt in this book (Quran) and Allah.
So you can think of the sin you might commit while reciting the verse falsely. While it is a good habit to recite the verses you don't remember by heart. But while doing so, you must keep Quran open in front of you, so where ever you think there is a doubt you can clear it through Quran.