DOES ANYONE THINK THAT AVATAR KORRA IS THE WEAKES AVATAR EVER!!!

No. The avatar will have a hard time learning the element that contradicts their personality the most. For Aang, the hardest element for him to learn was Fire because of it's destructive nature.

The reason it took Korra so long to learn to bend Air was because she is tough and strong, as well as hot-headed and impatient. Air was her opposing force, not fire, like it was for Aang. Let's not forget as well that Aang took a class and tried many different things before he met Toph, so no, he didn't actually learn to do it in a day.

If you forget, Aang only knew how to airbend at the beginning of the original show. In the first episode, we see Korra bend three elements. While she may be older in appearance, Aang was actually 112 when he mastered all four elements.

You're missing key elements in your argument, my friend. It took Aang all four seasons to learn to bend the elements. Korra has already mastered them over the course of 12 episodes.

Do you see my point?

Korra had already learned fire, water, and earth when they discover her at 4 or 5 years old. Aang only knew air at 12 when they found him. Also until Aang the Avatar didn't even begin training until they were 16. So Korra is right on track or even a little ahead of the past Avatars.

It's too early to say; she hasn't fully developed into an Avatar yet, so you can't necessarily compare.
She was learning in a very different way to Aang, being taught in a much more controlled environment that only allowed her to move onto the next element when she had mastered the one she was up to. You need to take context into consideration; Aang needed to master the 4 elements or the world would end. Korra needed to master the 4 elements because that's what Avatars do. Wasn't quite so much pressure,

but korra masterd all elements in one season aang took him more then 2