is there’s connection between krita to blender that because of it I see it a lot in “develop”?
No there is no official connection. Both group know each other and there are a lot of people / users who are both blender and krita fans/users. So the community is also somewhat common. Blender people use Krita for 2d work. One more common point is that both the foundations are based in the Netherlands.
Both being Free Software, people like to combine them and use them to create awesome works. And both have passionate community rallying behind them.
is there a were to know how to use blender?
YouTube has many tutorial videos for it, as you’d expect.
Blender had a significant change to its user interface a short time ago (I forget when) so the older videos may not be much use to a beginner.
If you watch them you’ll quickly realise that the interface isn’t the same as your new installation.
It was with 2.8 that’s why blender tutorials on youtube started to put the version in their titels. 2.9 again had some UI changes but not as big.
See this playlist to get started on it.