Carry out small improvements to the site on October Cms

Hello world. There is a ready-made layout of the online store, which is stretched on the October CMS engine. Plugins for creating an online store on October are also connected: Shopaholic, Orders for Shopaholic, ToolBox. Product categories, product catalog page, product card are configured. In general, I have already brought all the necessary information about the products out of the box to the corresponding pages.
Now I need help in setting up the cart and checkout pages (they are combined) and help in setting up the process of adding an item to the cart. That is, it is necessary to implement the ability to add goods to the cart by clicking on the "add to cart" button.
It is also necessary to add and display two methods of payment for goods on the checkout page. The first way: payment after consultation with a specialist, the second way: payment online on the site. In the first case - all the information from the form on the page when sending flies simply to the mail. Secondly , payment via Internet acquiring from Modulbank. Everything is already set up in modulbanks personal account. It is only necessary to configure the appearance of the payment widget after clicking on the "checkout" button.