Smal is in the sense that an item is smal like a small teddy whilst narrow is thin

Aliasia is right. We're just liberal with our usage of small in English.

I am focusing on getting 좋습니다, 좁습니다, and 춥습니다 because they are so similar. Take 4 or 5 of the words and make your own flash cards because duolingo is throwing way too many words at us.

unlike in english, korean pronunciation is very uniform. take some time to listen closely and after a while you will find each distinctive difference.
thats the only advice i can really give.

Thin