when do you use et and when est
You use "et" when you mean "and". You use "est" when you mean "is". They are both pronounced the same*, so you have to look at the context. There is also "es". Tu es beau. Il est beau. Tu es beau et intelligent. Il est beau et intelligent. I hope this helps.
*Edit - just realised, Sometimes, when people speak formally, you can hear the "T" at the end of "est" and the "S" at the end of "es". You never hear the "T" at the end of "et" - it is called a forbidden liaison.