My question is quite basic. Can one really learn guitar by himself? I recently bought this model and I want to start to learn the basics. My goal is to be able to perform covers
That depends on what your definition of "learn" is. It is not impossible to teach yourself an instrument or learn from tapes, videos, etc. But the likelihood is very high that you will have an up hill battle with respect to understanding basic technique and how to progress at a good pace. An experienced teacher will know how to correct bad habits in posture and hand position etc. This is crucial for making progress and avoiding injury. I have seen dozens of self taught guitarists develop problems due to incorrect hand posture and bad technique. Once these things are learnt they are hard to unlearn and many self taught musicians simply begrudge walking down the correct path. They tend to think classical training (or any training) is pompous and arrogant. Ironically, not being able to admit that training works is arrogant. Correct technique can feel uncomfortable to a beginner at first but once mastered is very natural. Poor techniques are like a drug, they yield quick results at first but eventually cause problems and lead to poor performance in the long run.
Of course, if you are only in it as a hobby you may be inclined to not care about technique details. But in my opinion there is really no reason to not learn to do it correctly. It won't cost a fortune to take lessons every other week for an hour and your progress will be regular and steady. Most people wouldn't think twice about taking a pottery class to learn pottery, or even swimming lessons at the local YMCA so why not guitar lessons? Learning an instrument, including voice, involves learning to master a part of your body and how to use it correctly. This is very difficult to express via a video.
Can "one" do this? There are lots of self-taught guitarists out there, some of them respected professionals, so it's possible in principle, and arguably it's easier today than ever before, with boatloads of instructional videos on Youtube, reams of free practice material on ultimate-guitar.com, games like Rocksmith etc.
Can you do it? That depends on your talent, your drive, and what else in going on in your life. You'll have to put in the hours, probably more so than someone with a teacher to guide them, and you should be careful and self-critical so you don't pick up bad habits.
Is it the best way to proceed? Depends on your circumstances - the availability and affordability of competent teachers, your personality and so on. I would recommend taking some lessons to at least put you on the right track, but if that's not an option... put in the effort to learn by yourself, and good luck!
With that particular goal in mind, you should be able to achieve quite a lot before running into problems that you cannot solve by yourself.
There are lots of tutorials out there, that teach you the very basics of whatever kind of music you are looking for. Based on how advanced your understanding/feeling for rythm is, you can choose to just learn the techniques and simple chord theory or also dive into music theory and learn how things are noted down.
Once you gained some experience in basic techniques, you can choose a song, find the chord structures (there is lots of material in the internet. Song books are also a good source), and try to get the rythm down by listening to it.
That is basically how I learned to play the electric guitar. I started 15 years ago (that is quite some time, it was already a lot of fun after 3 months), and now I do covers like this.
Yes, and no.
You are always able to lean an instrument by yourself. There are many self-taught pianists, guitarists etc. so you should be definitely able to play an instrument really good without the help of any teacher, the problem with this is, that you may miss some really helpful tips and tricks. Also you'll be much slower in learning things on your own, compared to learning an instrument with proper guidance.
There are also some problems with technique - for example: Of course you can learn all the scales on the guitar and piano and you should be easily able to play all of them in 'your' way. The problem is, that there are often more ways to get the same result. So if you use a really weird fingering for it, you probably make it a lot harder than it has to be and also if someone corrects you in the future, your brain will have a hard time to "overwrite" -your- correct way of doing it the past few years... It can be really hard to unlearn / relearn things again, if you have done them wrong for many years.