Nice work.
I'll add to hints already given...
6) The meaning of "listo" is unclear in context. It can take "ser" or "estar", depending on whether it means "smart" or "ready".
7) "Ser" or "estar" both would make sense, but the meaning of the sentence would be different.
8) "en 101" must be "en el salón / en el aula 101", but the verb is wrong.
11) Wrong verb in the first sentence.
16) Wrong conjugation.
Last comment: Many accents are missing.