Having taught guitar for many years, I see majority of beginners experiencing same problems and making same mistakes over and over again in their quest to learn how to play guitar. It's my job to steer them through these problem areas.
These "mistakes" are basic errors that most beginners naturally tend to make. But these mistakes can cause major problems if you allow them to become habits in your playing. Unfortunately, 90% of guitarists have done just that!
Avoid These 3 Mistakes Like The plague
The three main mistakes MOST people make when learning how to play guitar are:
1: Trying to play too fast too soon.
Don't be in such a rush. Trying to go too fast too soon causes serious problems. Sloppy playing and mistakes will become your trademark.
Learn to practice slowly and perfectly. The reason for this, is, what you program your brain and fingers with while practicing, is what you'll get as a habitual and subconscious end result.
The GIGO computer term describes it best. Garbage In = Garbage Out. If you program a computer with faulty data, your results will be faulty too. It's exactly same with learning how to play guitar.
So practice everything very slowly and perfectly. Do this, and your playing will be to a higher standard than 90% of all other guitarists. Yes - even those that have been playing for years!
2: Too much body and hand tension.
Have you ever noticed how top professionals make it all look so easy and effortless? How relaxed they are?
Take a lesson from that.
When learning how to play guitar, and in all practice sessions, you need to be as relaxed as possible at all times.
Unnecessary tension anywhere in body when playing will stop you like a brick wall. Any "excess" tension in your fingers, hands, arms, elbows, wrists, shoulders, neck, chest, stomach, thighs, legs is extremely hazardous to learning how to play guitar properly.
Practicing right things in right way will give you amazing results - even if you practice only 10 - 20 minutes a day.