I guess you are going to get different reponses, ultimately you have to find out what works for you. In my case, I started learning songs as soon as I could, because I wanted to be playing something. My 1st via YouTube was Wish you were here. Since joining GT I concentrate on their library.

For me personally, I get the chords down, meaning I can make the shapes. Then I start trying to get the tempo down. It sounds pretty bad. But with practise things come together and I get better at the chords and can keep pretty good time.

Thats how I do it. Good luck.