Are the below sentences correct?

English as a Second Language English Vocabulary, Grammar and Idioms
1
  1. We will need a volunteer. The volunteer will function as guest attendant in the cat room and assist customer with their enquiries and needs. The volunteer will also need to explain the rules and regulation of the cat room.
  2. The volunteer will perform duty as guest attendant and handle explainatory task.
  3. He will be in charged of recruitment/employment.
  4. She will give explanation and give lesson about cats to the customers such as cats body language and so etc.
  5. I am calling to inquire about the plumbing services you offer.
  6. I am calling to inquire about plumbing services that I need for commercial unit.

Are the above sentences correct? Please advise.

2
  1. We will need a volunteer to be a guest attendant in the cat room and assist customers with their enquiries and needs. The volunteer will also need to explain the rules and regulations of the cat room.
  2. The volunteer will perform the duties of a guest attendant and handle explanatory tasks.
  3. He will be in charge of recruitment/employment.
  4. She will give explanations and give lessons about cats, such as cats’ body language, etc. to the customers.
  5. I am calling to inquire about the plumbing services you offer.
  6. I am calling to inquire about the plumbing services that I need for a commercial unit.