For English speaking people, that is people who speak English, or a dialect of English there is very little culture shock. The local dialect is easy to understand, and British terms are used, which can be different to the ear, if you grew up with a dialect of English rather than British English. There is also a colloquial dialect, but it is also a dialect of English.
Courtesy is probably the first thing that sticks out. Whether it is giving someone the time of day, while passing someone on the road, or getting on the bus, or to giving someone a break in traffic who is trying to cross traffic. Driving is on the left, but it does not present too much a problem to those who are not accustomed to driving on that side. For me I had to switch the mirror on my bicycle helmet to the other side. Also, the first thing you say to anyone, whether in a business or out in public is to give the time of day, before you ask a question or start a process. If you want to get anything done in Barbados, courtesy counts big.
Anything you need or want, you can probably find as there are many stores and businesses. For those things you can't find, you can use any one of a number of shipping companies that will bring to you what you want, and of course providing that you pay the customs duties.
I did not personally feel any culture shock and I do enjoy the culture.