Question

Me expliquem de uma maneira que dê para entender, o There be- Past form, por favor, minha prova é amanhã!!!

Answer 1

there be é facil

o verbo there to be significa haver em portugues  e é o conjunto assim:
                          singular            plural
simple present     there is           there are
                            há                    há

simple past         there was         there were
                             havia                 havia

observações :
was not : wasn`t
were not: weren´t

short answer
exemples -  was there a fat boy here?
( havia um menino gordo aqui?)
yes, there was
no, there wasn`t

- were there two fat boys here?
( havia dois meninos gordos aqui?)
yes, there were
no, there weren`t

vc sempre troca o o verbo de lugar na pergunta e na resposta vc volta ele no lugar.

examples

affirmative
There was some sugar here.
negative:
there was not any sugar here.             SINGULAR
interrogative
Was there any sugar here?

affirmative
there were some potatoes here.
 negative
There were not any potatoes here.         PLURAL
interrogative:
Were there any potatoes here?
   
Vc deve ter notado a questão do any e do some
 some vc usa na afirmativa
any vc usa na interrogativa e na negativa

Espero ter deixado claro e ter ajudado.