I set up a cloud using OneCloud on my Raspberry Pi, but I discovered that it can only be accessed within my home network. I cannot access it from anywhere else.
I used this tutorial: Install OwnCloud on your Raspberry Pi. Please help.
You need to set up port forwarding on your router. Then you can use your (router's) public IP to access your raspberry pi from outside.
To access the OneCloud from other networks you need a domain of your own. Seen from outside your home network, the raspberrypi will be not having the IP you gave it but a global address given to your router