Self powered USB Hub
If you are connecting devices which use more power than your Raspberry can provide, you will need a self powered USB Hub.
You can start connecting devices to the raspberry and switch to a self powered hub when you start to see strange behavior of the devices.
Hubs with FE1.1S chip work right, avoid hubs with MA8601 chip. Often the same model can contain any of them. And some of them do not contain chip at all! just a glob of black material to hide what is underneath ... nothing.
It would be a good idea to get a Hub with 5V input so that you could power it with the same source as your Raspberry.
You can also get a Hub with 12v input. Sometimes those devices have an output to charge phones or tablets which probably you could use to power your Raspberry.