I know L said Light was his first friend but did he mean it? Yes we know L is a liar and knew Light was Kira the whole time but what if, during the time Light lost his memories, L thought of Light as a genuine friend. It’s all very confusing to me still so can someone answer?
So here's the thing, the author of Death Note, Tsugumi Ohba put little notes and other trivia in Death Note 13: How to Read. And some even asked if L was genuine about him being friends with Kira. To which he answered "No" as L was lying to catch Kira.
L Has No Friends?
Nope. And when he says that Light is his first friend that's a big lie. He never considers him a friend. He probably secretly thinks really negative things about him.
L did have emotions but Light not.
L really considered Light as a friend, but at the same time was sure that Light was Kira. We can see that when L was dying (ep. 25), L was regretting that he is sure that Light is Kira, but has no way to prove it. So he still showed gratitude to Kira, and wiped his feet.