space=I have a very many space to sit.
>> There are a lot of spaces to sit.

shape=I like very many shapes because it is very cool.
>> I like a lot of shapes because they are very cool.

everywhere=I think I go to everywhere I want to go.
>> I think I will go anywhere I want to go.

Everywhere means "in or to every place".
Example: I've looked everywhere but I still can't find my pen.

blow up=When it is Fall the leaves are going to blow up.
>> In fall, the leaves (?)

Leaves don't blow up. They change colors and they fall to the ground. When we say "blow up"- it means "to burst" or "to explode".

change=I like to change up when I go to outside because it is very hot.
>> I like changing clothes before I go outside because it is very hot.