what is Create wallet using blockchain api (PHP)
This API allows you to create a new Wallet on Blockchain.info. It's the same as if you are registering on the webside but programmatically. On Blockchain.info you can do all thing either of the website or programmatically, which can be very usefull.

If you want to call the api from PHP, you need to send a JSON-Request to https://blockchain.info/api/v2/create_wallet. For a tutorial of JSON-Request in PHP look here

For sending and receiving Payments you need to use this api:
https://blockchain.info/api/blockchain_wallet_api
There are also some examples in PHP on this site.

Blockchain.info does not offer a referral programm, so there is no reward for providing new users.