As an application developer you will only need to author and deploy a single smart contract. These docs will help you do that.
After completing that step, you will want to proceed to the next section, to learn about connecting your Dapp to a statechannels-compliant wallet.
This section is for developers building browser-based Dapps that require a browser-based state channels wallet. Server-based applications should use a state channel wallet library (coming soon).