[konbini]

Given what was discussed early, this probably sounds like a stupid question. I am confused about when it sounds more like a l or r.
When I was in Japan a Japanese friend told me their is no difference between l and r. He gave the word for apple as an example. To me it sounded more like linguo than ringuo. Also I remember ordering ramen and the woman called it lamen. Would it be incorrect to say toli instead of tori or aligtou instead of arigatou?