A Rainingy Day andwith Children

Today it was cloudy all day and now it is raining a little.

I'am watching to two children within gumboots, jumping into allevery pools that they find in their path.

You can either write "I am" or "I'm".
The word "gumboots" is commonly used in Canada, Australia and New Zealand, but it is less often used in the U.S. ("rain boots" or "rubber boots" are used instead), and I think it is considered dated in the UK ("Wellington boots" are used instead). This might be relevant if you are focusing on a specific version of English, like British or American English.

It's curious, I remember that when I was a child that, I liked walk oning in the littler pools that were made when it rained, too.

For some reason, this do happy tomakes children happy.

Includeing myself.

Rainingy Day and Children

Today it was cloudy all day and now it is raining a little.

I'am watching to two children with gumboots, jumping into all pools that they find in their path.

In American English we'd say 'rainboots' rather than 'gumboots'

It's curious, I remember when I was a child that I liked walk oning in the littler pools that were made when it rained too.

For some reason, this do happy tomakes children happy.

Includeing myself.