How to push an image to the right and raise it to the top 300?

It’s a radial linear gradient that creates the dots and sets a repeating pattern of 33px.

  background-image: radial-gradient(
    circle at 2px 2px,
    #cde9fe 2px,
    transparent 0
  );
  background-size: 33px 33px;

A gradient is basically like a background image and can be managed like a background image.

Here it is just on the body element.

Here it is as a background to a div.

Here it is as a partial background to a div but requires a pseudo element to limit its scope rather than covering all the div.

https://codepen.io/paulobrien/pen/WNajLGG

It’s very simple code although the actual construction of the gradient is quite complicated but luckily there are many examples around the web you can borrow from or modify to get what you want.