Resize Image on blogger

[Yukha]

I know it's really a silly question:v

So i just made a blog for my assignment, i'm using Vienna Theme which is free.

And made some small edit on widget etc, but when i open my blog my first post image resized till it's reached the maximum post block.. https://imgur.com/a/27Wcy

https://imgur.com/a/6ggm4

Please help me : / i dont know well about html and javascript