What is easier, playing a guitar standing or sitting?

If you are a sit-down guitar player you should make an effort to practice playing standing up as well. Two good reasons for that: it will make it more difficult to look at the neck when you play and consequently you’ll learn the neck in a new way. Also if you’re ever called to play standing up you’ll have some experience at it, having practiced that way before your gig. I would guess though that a stand-up guitarist probably spends plenty of time playing seated anyway… so I guess I’d say it’s easier to play guitar standing or sitting if you have, in fact, practiced that way a bit. However you do it, don’t forget to have fun!

Is a string winder necessary to change guitar strings, or can you just use your hands?

Time saver for sure. But I think there may be some value to winding your strings by hand, at least until you know you know how to do it. There is a certain – elegance – to the ritual, for me anyway. Paying intimate attention to the equipment. Stretching the strings to their proper tension and focusing on the tiny changes that make the tuning correct. I miss that when I use the winder but of course, the job gets done quickly.

What is the best guitar for a beginner?

Classical guitar, imho, if you’re thinking about learning guitar.

Wide neck, so easy to see when your fingers are supposed to be, whether you have little skinny kid fingers or big fat hand sausages. And nylon strings are so much easier on new guitar player’s fingers. No need to plug it in so you can play it without an amp. Makes a pleasing sound right from the git-go. Relatively inexpensive- you can get a quite decent one new for about a hundred bucks. Looking at some of the other answers though, I can see “easy” means different things to different people. “Playability” is certainly the key here and that means a nylon string guitar to start out, to me anyway.

Why can’t I change guitar chords properly?

Because you are trying to do it too fast. Try this: slow waaaay down. Put your fingers in position for the first chord and play that, Now slowly move all your fingers to the next chord finger positions- very slowly and deliberately. Don’t play the chord until you are absolutely sure about your finger positions. Are they correct? Are you sure??? Play the chord. Now back to the first chord. Once you’re sure about the finger positions (and not before) play the chord. Now back again. now do that- oh, I dunno- about a thousand times maybe. At some point you’ll have those two chords in muscle memory – you probably won’t even notice when that happens exactly. Once you have them, move on to a couple of new chords. Mainly- go glacially slow. You’ll get it, I promise. Good luck!

I would not concern myself too much with mastery. Instead, how about making yourself happy? Learn a couple of tunes! I don’t think there are too many better ways to calm your mind and improve your mood than playing guitar.

I have been puzzling over playing guitar for close to 50 years and it is only now beginning to make sense to me! And I’m a pretty bright guy, IMHO. I can tell you what helped me was focusing attention on modal scales and the notes on the 5 and 6 strings. But understand this- it’s easier for some folks for sure but I don’t know anybody who gets the neck without a lot of hard work. You’re in good company, certainly. Keep at it!

I may be biased, but by far-
the best to start on is guitar.
The reasons? too numerous to count
so here are just a small amount:
it’s portable, it’s cool (and cheap-
to buy one you don’t need pockets deep)
With six or seven chords at hand
play tons of songs by any band.
No girl to call your own, my friend?
take up guitar, and that will end.