How do you use the word and I in a sentence?

You can't use "and I" as a complete sentence on its own. It needs to be part of a larger sentence. Here are some examples:

* "My dog loves to play fetch, and I love to throw the ball."

* "We went to the park, and I saw a squirrel."

* "The cake was delicious, and I ate the whole thing."

The key is that "and I" should follow another clause, like "My dog loves to play fetch" or "We went to the park," to create a complete sentence.