I have several IRL friends that play this game and are struggling. They die needlessly, farm poorly, and lack knowledge about their champions. They have all been level 30 for a while too. Two of them only know 2 roles and one of them knows only 2 champions. I don't want to slam them because I am certainly not pro but they are consistently struggling. They also do not take advice well and I unfortunately dread playing with them. I have tried giving nonjudgmental tips and have shown them some guides with no success. I have made it a point to try and get in game before I have to queue with them. Help?

I agree that it remove some fun when your teamate dont want to learn or take advice. such as pushing/extending to much, 1v2 suicide, no help with team fights etc etc... Especially when you ask them and they keep doing it.
I found that, when I stay polite and good manner, it end up ok with these kind of person.

Personnaly, I wouldn't queue with them if your planning to have a good game or a ranked game for instance. The goal of a game is to have fun, so as long as you do have some, who cares. But if you want a serious game, it's another thing.

Im far from a pro and it's not my goal to become one. But Im sure able to help others and able to receive tips from others to. Even if most of the time its like OMG STOP FEEDING YOU FKIN NOOB at 0-1 XD

Yeah one I haven't played with in a while because they die a minimum as 8 times typically while getting one maybe two kills. I really want to play with one of these people though because they want to get better (or so they say) but will not take advice.