The first thing to realise if you are building a website or setting up as an affiliate ( a commission based online salesperson) is that you have to find your 'niche' market- using 'Keywords'.
Keywords are the very first step! Too many people think of a name for a 'Domain' they like, rush off to buy it before considering if anyone is out there actually searching for their product (or domain name) on Google ( or any other 'search engine')
This is one of the biggest 'traps' for a new player in the game of IM (Internet Marketing).
So- do your homework! ( I know - you thought you'd gotten away from this working online?!)
Then, consider if you want only a .com site- or perhaps a local version as well....com.au for example.
There are many good Domain providers out there - I use 'Go Daddy' for most .coms and 'Name Cheap' or 'Hostess' for local Australian names.
Register your Domain for 1 year (particularly if just starting out) to conserve funds and then get a good 'hosting company- I like Hostgator but here are many others....You will generally need an ABN number to do so, so be prepared and set up as a Sole Trader as a baseline.