Playing with friends | No rating

Yes.  Unrated.  I know you can do it in Daily, not sure about Live.

In Daily you go Play>Daily>Play>Custom game>and then move the toggle switch to unrated and Play.

Yeah, under custom you can go unrated in Live too.  Who knew?

I did  I play lots of unrated games with friends and usually annotate them afterwards. It is a friendly way for both players to learn from their games without the pressure of "taking" away their rating.

How do you play an untimed and unrated game with a friend? My grandfather would love to play but he needs some time to think! Thank you for your response!

When you are creating a challenge to send, you can make it unrated there. You can't make a game untimed, but you can always add time mid-game in 15 sec. increments if you need it, but more likely is just give a huge time control like 5 hours per side or something like that so you are fine. 

Alternatively, daily format games are 3 Days per move as a default. Those games game easily last months. You could even increase the time control to like 14 Days per move if you wanted, but this is plenty of time I think