I tell from my experience as I've been able to learn acoustic guitar for 10 years. These are the the 4 tips that ultimately lead to my success.
1st: Keep yourself fun and motivate
2 years ago when I decided, when I thought to myself "I'll learn to play guitar once and for all, at that time was with a girl, well the thing is, I was fascinated to see the effect it had in women when you are playing a song ..
I wanted to do the same, saw on television, as in a reality show, a man playing a song to a woman and she was fascinated and then she ended rendered to it.
Maybe it sounds very pretentious, but I wanted to make the same impact with my girl, and in general with women, when going to the beach, guitar, play it would be a great strategy for meeting people.
2: Find songs you love to make guitar learning more fun and not boring
Nothing that really made me learn guitar acoustics but only music that i love. Find the song you like to listen too and easy rhythm to strum. Just strum 4 beat: 1 2 3 4 downward only at first just to keep the rhythm right to get the hang of the song.
4: Just play the next song
Find more songs to master just the 1 2 3 4 easy strum but keep it constant. Then you will find that playing acoustic guitar isn't that hard at all. It's just a matter of getting the feeling of the song and progress to more complex strumming. Good Luck!