How to set up an order form?

How can I allow a user to select multiple items, a quantity for each item, a total for each item, and a total for the whole form, including all items.

From what I could see at the form you've shared, I can suggest creating an order form.

You can get more information from our detailed guides:

Setting-Up-Your-First-Order-Form

If you would like to sell your products or collect amounts and process the payment offline through check or wire transfer, use the Purchase Order payment field. Since no payment is required to submit the form, your form will work just like a normal form.

How-to-Create-Payment-Form-with-Purchase-Order

Hope this helps!But, let us know if you need further assistance.