Website Completion with Forms and Payments

I need help finishing my new WordPress website, including adding multiple forms and payment options for several digital services. I also need plugins added so I can upload digital media to multiple pages and make it downloadable for interested visitors. The right freelancer should be able to complete these updates efficiently and ensure the site works smoothly for both users and administrators. I'm open to suggested changes in theme or plugins. The site is here if you would like to review it first: https://thesocialbookshelf.com