is 700 a good rating

More players should comport themselves like this Man ^

I have two friends who left this site because they grew weary of the abuse-as-entertainment by elite tier players toward low skill members, here.  Short-sighted and stupid stuff.

Nice

Yeah not so good.

Don't worry too much about your rating. It'll come with time. But at our level, the best thing we can do is slow it down a bit, 30 min games. Allow our minds to start developing deep thought. As you work through patterns logically over and over rather than instinctively. They'll start to solidfy and you will see them quicker.

you are doing fine!

it does not matter what other people think of your rating. what matters is what you think of it.

if you are happy then have fun and play chess!

if you are not happy with it, then it is time to start putting work into your games.

you know the flexing is bad when you put your elo in your username

The simple answer is no. The complex answer is "it depends". What is good is subjective. Some people who have nearly your exact same experience in chess might be 200 rated and others might already be above 1200 or higher. For instance, I'm about the same age as Carlsen and started playing a few years after he did, yet I'm completely garbage in comparison. I still make terrible blunders and the worst part is that I often think they were good moves until post-game analysis.

No.

Chess.com rating is definetely underrated. It says under 1,000 is beginner. BUT! Ive played chess from childhood as an amateur, on chess.com i have played 1405 Rapid (15 minutes) games, 91 Blitz games and i am still 640. A friend of mine has bllayed around 6,000 bullet and blitz games, and he is under 600!!! Weve been playing actively for at least 3 years. My nephew takes chess lessons and has a grade in chess (3rd razryad (grade) as per the Soviet ranking) and i won over him. So there is smth definetely wrong. Can someone explain ?

Beginner (Under 1000): Players in this range are usually learning the basics of the game, including opening principles, basic tactics, and endgames. 
Intermediate (1000-1800): Players have a good grasp of basic strategies and tactics and are working on more advanced concepts.
Advanced (1800-2200): These players have a strong understanding of the game and are often involved in competitive play.
Expert/Master (2200+): These players have a very high level of skill and understanding of chess.

But maybe its actually his birthyear ?

SCNR