If you would like to charge someone just for a coaching package to have them sign up so it's not connected to any kind of course, you have two options. First, you can just send them a regular invoice and do it that way. Or the second option is you can create a product and connect it to your checkout system.
To create a product, go to Payments and Products and select "Create new product".
Name your coaching package and add a description of what is included.
For your product type, select "Service", and give it a pricing.
If it's a one-off price, you can add it here. There's no need to connect it to a membership offer since it's not a digital product.
Select "Create this product".
Now that you have created your product, you can come to your sales page, go to your checkout, and connect the product. Search for your coaching package and add the price. You can also add a bump order if you would like.