Please let me know if I used the correct grammar and expressions. Thank you!

Hope you have had (or had?) depending on whether their holiday is over or not yet a nice holiday.

I am sorry for my late reply but both Stephen and Charlotte are taking their swimming lessons next week so I was waiting for them to confirm the dates/times for the appointments.

Please note that I am (or will be) both possible available meet you on Thursday 9-11am or Friday 10-12 next week and hopefully it is convenient time for you and other colleagues as well. I look forward to seeing you again soon.

By the way, I just heard Tom had left the company. It is really sad news as he was a such friendly colleague. Please give him my regards if there is a chance.

Thanks again! Take care!

Please let me know if I used the correct grammar and expressions. Thank you!

Hope you have had (or had?) a nice holiday. [If the holiday is still going on use "have had", if the holiday is over just use "had."]

I am sorry for my late reply, but both Stephen and Charlotte are taking their swimming lessons next week. so I was waiting for them to confirm the dates/times for the appointments. [I broke this sentenc  up becuase it was getting very wordy. You could also write it as "I am sorry for the late reply. Stephen and Charlotte are taking their swimming lessons next week so I was waiting for them to confirm the dates/times for the appointments.]

Please note that I am (or will be)  ,or will be, available to meet you on Thursday 9-11am or Friday 10-12 next week. and hopefully Hopefully it is convenient time for you and other colleagues as well. I look forward to seeing you again soon.

By the way, I just heard Tom had left the company. It is really sad news as he was a such friendly colleague. Please give him my regards if there is a chance.

Thanks again! Take care!