There's certain situations that arise that I don't know how to handle and need input.

So, the new company asked me to join their company-wide Zoom call this week, the week before I officially start work, because my new boss will be out on vacation the week I do start. So, that's a bit odd to me, but whatever, I said I would love to and will play it by ear given my workload and current demands. So, that Zoom call is on Wed - I just received the invite but haven't RSVP'd yet. I think I should attend simply because I've been invited and I feel its' the right thing to do, but I really don't want to do this this week, while I am still working at my old company. I find it to be a bit strange to straddle both simultaneously, and I will have to also ask my boss if I can work 8AM-5PM instead of 8:30 AM-5:30 PM in order to attend this meeting.

The second situation I don't know how to handle is my current company is also scheduled to have a company-wide meeting, this Thursday. Thurs is the day before my very last day of work. It's already been announced via email that I am leaving, I already had a goodbye zoom call with most members of the company, and I don't really want to be in the spotlight OR attend this company-wide meeting on Thurs -- I think I have to though? Often times, the CEO will bump the meeting to the next week, but I don't want to ask him to move it until after I am gone, and I also don't want to attend. Not sure what to do??