First time paid Event Photography in a ballroom. I have questions. Any good tips?

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Hi, I've been shooting semi-professionally for a few years for work events and whatnot. It's usually smaller scale. I'm actually getting paid decently and want to ensure that I'm taking my best steps so I can hopefully procure future work.

I will be shooting in a ballroom which I will post pictures of. Looking at other photos the ceiling is white. I want to know if I should try to bounce my flash or use a white bounce card in case the ceiling is too tall?

I was instructed to take photos of event speakers, how many shots do you think I should take? There are 5 speakers over 1 hour, obviously I won't be shooting the whole time. In your experience do people want photos of guests listening or eating for a corporate event?

Then a reception to follow. I will probably have to do posed portraits and that's what I'm concerned if you think I would need much flash? It seems pretty well lit.

I also have a Sony A7IV and a Tamron 35-150. Do you think that is enough length to get the speakers in enough detail?

This was spur of the moment, a good friend asked me to do her a favor and I agreed. I would love to have shadowed a photographer first but I already agreed!

Thanks in advance!