How can I help my friend enjoy league of legends?

I've been playing this game for several years now and my best friend told me that he was gonna play it now since he was finally interested and hooked. So I taught him a bunch of things on league about the champions he played and was against, the items to buy, the purpose of each lane and etc. He enjoyed it at first cause he played adc and I'd play as his support so he can get kills and gold and be satisfied, but he was getting bored from it and stressed out. So i inspired him to do whatever on the rift but it was still boring and stressful. I think its because he just plays the same person (draven) over and over again and not trying out new people... I'm not sure.

help.[zombie-nunu-bummed]