A Proxy is a smart contract that allows you to easily interact with supported protocols, including the Maker Protocol, to manage your Vaults, generate Dai and so on.
You will only need to do this once per wallet and all your Vaults will be managed through this single Proxy. Please never send any funds to this Proxy address.
"I did my first transaction and I still don't have an open vault"
If you did your first transaction and still don't have an open vault that's because the transaction was used to open a proxy for you, so it can manage the Vault in your account.
After this first transaction, you should be able to open a Vault and generate Dai normally.
"Do I have to keep paying fees for the proxy?"
For any other type of collateral or operations in the same account, it will not be necessary to create another proxy, so you can rest assured that it is a one-time gas fee. Also, this fee goes directly to the Ethereum network in order to setup all the necessary prerequisites for interacting with Oasis and the underlying technology.
"How can I know if the proxy was created with success?"
You can go to Oasis dashboard and check if it is already possible to create a Vault or you could simply check the status of your transaction in a blockchain explorer. The "Maker: Proxy Registry" set at address 0x4678f0a6958e4D2Bc4F1BAF7Bc52E8F3564f3fE4 is the contract responsible for creating a Proxy. This check is not needed, you don't have to do anything besides following the steps in Oasis' interface and this will guide you on your way to open your first Vault.
The Proxy module contains contract interfaces, proxies, and aliases to functions necessary for both DSR and Vault management and Maker governance.
The Proxy Actions contract is a generalized wrapper for the Maker Protocol. It's basically a set of proxy functions for MCD (using dss-cdp-manager). The contract’s purpose is to be used via a personal ds-proxy and can be compared to the original Sag-Proxy as it offers the ability to execute a sequence of actions atomically.
For more technical information, please refer to the documentation.