First gGuitar

Title so all important words need to start with a capital letter.

It's so hard to do it.

Don't need "it".

I used many kinds of resources, but so many men, so many mindthere are so many different opinions.

Probably don't need "kind of". So many men, so many minds is not a saying we would use in English.

One person says that this guitar is suitable for beginners, and the another talksays that the guitar is better.

That already talks about a specific guitar you don't need the.

I wannajust want to choose just a good thingone: not cool, not professional, just good for a beginner teaching.

wanna is slang not what you would use to write normally. Good thing not correct expression here. At end think "just good for a beginner" sounds better.

My First gGuitar

It's so hard to do it.

I used many kinds of resources, but so many men,there were so many mindopinions.

One person saysid that this guitar is suitable for beginners, and the while another talks that about how another guitar is better.

I wannat to choose just a good thingone: not cool, not professional, just good for beginner tleachrning.

It' was so hard to do it.

You would want to use the past tense, since this story happened yesterday. Also, the "to do it" part is slightly redundant, so you can omit it :)

I used many kinds of resources, but so many men, so many mindpeople had different opinions.

I understood what you meant by "many men, many minds", but I thought I'd provide a more common/widely understood phrasing.

One person says that this guitar is suitable for beginners, and the other talksays that anothe guitar is better.

When quoting someone, be sure to use the verb "to say" instead of "to talk."

I just wanna choose just a good thingone: not cool, not professional, just good for beginner teachings.

When referring to a specific type of object that's already been made clear (in this case, a guitar), say "one" instead of "thing."
"Beginner teaching" would imply that you're the teacher, whereas if you're learning on your own, where as "one for beginners" shows that you're teaching yourself.

It' was so hard to do itchoose.

I usreviewed many kinds of resources, but so many men, so many mindpeople had very different opinions.

One person says that this guitar is suitable for beginners, and the other talksays that another guitar is better.

I wanna choose just a good thingguitar: not cool, not professional, just goodsuitable for a beginner teachingo learn.