Internet Service Provider ISP Host your website, help in Domain name Application, If there is someone have the Domain Name you apply, You need to choose other. Domain Name in Internet is unique

Software House write CGI program for your business, design the required software, setup the software for Credit card payment. develop the homepage and the product webpages. Then test and debug. Upload to your website.
If you are familiar with CGI program and software you may do it by yourself, But you need to take all respond

To apply Credit Card Merchant Account needs an Amount of deposit, a definite sales transaction requirement. Your financial needs up to a certain standard. In each transaction, the bank will need a ratio of handling charge

In real life, there are some financial companies help people to develope Internet shop who cannot meet the standard of bank, But we will not discuss at this moment