Sell multiple products as one product (bundles)

I want to sell a bundle of two or more products as one product. So the customer doesn't add these one by one but chooses one product to buy, which is a bundle of multiple products in my store. On the checkout, this shows as multiple products, yet for a bundle price. For example, I have a course that I sell for $100, and now I want to add a membership to that, which is free for the first year as a bundle. But I don't want the customer to click it to choose the Free product, but that it is added by default.