Sure! You can do everything already. However, when you upload
without pledge tiers you can only make everything public. No
problem, I think. You can set-up all of your tiers, and specify your
rewards. Patreon is like a bank without paying interest. You can 
leave the money there that you will receive, and a bank account
or PayPal account is needed when you want to transfer your income.

So I think you can start right away with finishing your site.