Hey!!
Using ser in a sentence:
Now first off, you need to understand what ser is. Ser means "to be".
Sentence: Yo soy ciudadano estadounidense. It means: I am an American Citizen. Soy is a yo form in ser. There are many ways to write a sentence using ser form. Let me offer you some more examples: Son las once. Means: It is twelve o clock. Another: Ellos son intelligente - they are intelligent.
Moving on to using estar:
Estar is similar to ser, but they're different. Like here are some sentences:
Yo estoy feliz - I am happy.
Ella esta hablando - She is talking
You use them in verb,
Hope this helps!!