Hi, mylifmydream!

‘es’ is the third-person singular of ‘ser’ in Present.
‘está’ is the third-person singular of ‘estar’ in Present.
‘se’ is a personal pronoun (third person singular or plural, feminine or masculine) You can’t mix it with the two above)

For the people starting to learn Spanish the difference between ‘ser’ and ‘estar’ is quite difficult. A main rule is that ‘estar’ is for transitory situations and ‘ser’ for permanent situations.

e.g.

• Él es un hambriento (He’s an starving person)
• Él está hambriento (He’s starving)

I hope this help you at least a little bit ;)

Greetings from Galiza,
ifrit