Learning the acoustic guitar is not difficult but what can be a little tedious is wading through the swamp of advice from friends, family and the internet. Come to think of it, a lot of advice is better than no advice so maybe it's just a question of organizing what you want to do with your music. What's your plan with learning the acoustic guitar?
If you don't know the first thing abour the guitar, there are books available that will give you the basics. There's a couple of books you should at least take a look at. Guitar For Dummies is a great tutor for the acoustic guitar student who doesn't want to embarrass himself by asking silly questions. If you want all the knowledge of any kind of guitar playing before you even need it, take a look at the guitar books published by Mel Bay. Many guitar players swear by them.
If you see yourself as a casual acoustic guitar strummer who just wants to be able to play his favorite songs and impress girls at parties, then you will probably get all the info about technique and repertoire from the internet. If you feel you want to be seriously interested in playing the acoustic guitar, think about getting at least a few lessons from a guitar teacher.
Yes, you can learn a lot from just reading tab and watching clips on YouTube but a teacher can show you scales, holding the plectrum properly, fingering positions and how to get a good sound. It is a much faster and more effective way to get your basic questions about the learning the acoustic guitar out of the way.
The fact is, many amateur guitar players have spent years teaching themselves and been amazed at how musch more they have learnt when they finally spent some money on lessons. While we are on the subject, there are two kinds of teachers, one kind gives you knowledge about the guitar, the other kind teaches in a way that prepares you to go back to your room and teach yourself. Try and find the second kind. If you are going to apend money on learning acoustic guitar, you may as well do some research.
The question of whether to learn to read music always comes up for people learning guitar but if you want to learn songs quickly without becoming a soloist, tab and chord charts are the way to go. Also once you have some familiarity with the guitar, you will be surprised to find that you will develop the knack of inserting solo breaks into your playing.
One thing that all people learning acoustic guitar encounter is discomfort. Your left hand finger tips need to develop callouses, you whole body needs to learn a new range of sitting, standing and arm moving positions to accommodate your guitar playing. Basic advice on this subject is most of the physucal obstacles you go up against will disappear within a short time, but if you are getting any kind of real regularly repetitive pain, stop playing for a day or two. If the pain starts up again, get some advice from a doctor. Playing through the pain is not a good idea.