“If you’re planning to buy a new MacBook Pro, make sure you set aside a considerable amount of cash for the adapters you need. Apple doesn’t include any in the box, except for a power adapter.
Your best bet is to get a combination dock, like the Satechi Slim Aluminum Type-C Multi-Port Adapter ($60 on Amazon). It connects to the MacBook Pro via USB-C, and includes a USB-C pass-through port, two USB 3.0 ports, and an HDMI port with 4K (30Hz) support. With this, you don’t have to carry around multiple adapters.
If you don’t want a dock, or you can’t find a dock with the mix of connections you need, Apple or another company probably has an adapter for you. We’ve come up with this guide to help you sort out what you need…”
Roman Loyola at Macworld has a great overview of all the various connectors and adapters you may need for the new MacBook Pro (and also the existing 12″ MacBook). It’s a shame this has become so complicated. The promise is that USB-C will take over for most of these connectors, but weren’t we told the same thing about USB-A, then Thunderbolt?
Source: All the adapters you need to buy for the MacBook Pro with Thunderbolt 3