I could probably count and answer you but it's like asking how many clothes someone has at home. We each have different needs, wants and habits.
It's nice to be able to go a couple weeks before needing laundry
facilities but it's not mandatory. Do you change your clothes every day? Your undies and socks? Do you even wear undies and socks?
You may find that you occasionally need a shirt with a collar and a pair of slacks or shorts (not jeans) to eat in some of the dressier restaurants. Or not.
I think the best plan is to start boating
with what you think you will need, then make adjustments based on your own experiences.