Most sellers are happy to ship everything to you in the same package, if you're buying multiple items from them.
You may get a discount on shipping, because the seller saves money by combining items.
When you add an item to your bag, you will see whether or not the seller offers a discount on shipping when you add additional items.
If they do, add the items you want to buy to your bag and you'll see the combined shipping total in your bag and at checkout.