Existence.................Existencia
Life..........................Vida
Being [noun]............Ser  (this is a noun and a verb, as in English)I must say, I don't know
if you are aware of this, I suppose you are, but in Spanish
there are two different verbs for what you call "to be": SER and ESTAR. It's a bit complicated to
explain when youshould use either but basically SER is something more permanent and ESTAR is more
temporary (though not always).

Also, (I don't know how precise you want to be) we have two pasts (or three) for this.
If you want any further info,
tell me exactly what do you need and I'll help you

I was......................... Yo Fui / Yo estuve
he was......................El fue / El estuvo
they were..................Ellos fueron / Ellos estuvieron    (femInine for Ellos is Ellas)
I am.......................... Yo soy / Yo estoy
you are.....................Tú eres / Tú estás
He is.........................Él es / Él está
they are.....................Ellos son / Ellos están
I will be......................Yo seré / Yo estaré
he will be...................Él será / Él estará
they will be................ Ellos serán / Ellos estarán
there was.................. Había   (this is a strange verb that doesn't exist in english)
there will be...............Habrá
it existed..................existió (it also means she/he existed)
Finally ten short sentences. [please put the 'existence' word in brackets]
example:
The girl [is] a student.

The girl is a  student......La chica 'es' una estudiante
The boy is being kind.....El chico 'está' siendo amable
The building has existed for ten years......El edificio ha 'existido' por diez años
The girl is running quickly..............La chica 'está' corriendo rápidamente
The boy handsome.............El chico 'es' hermoso
The man is adoctor..........El hombre 'es' doctor
I believe in the existence ofatoms.....Yo creo en la 'existencia' de átomos
Life exists onearth........La vida 'existe' en la Tierra
I like being student..........Me gusta 'ser' estudiante
I enjoy life......................Yo disfruto la vida
I feel love for him/her with my whole Being.....Yo siento amor poe él/ella con todo mi 'ser'