There is a difference between "checkout" and "check out". "checkout" is not a verb, but a thingamajig. "the checkout page". "to check out" is a verb.
The first proper word on the blog seems incorrect. That doesn't inspire confidence. There are a few more problems with the text such as (preposition) words that appear missing, for example.
"its completion" -> "it's completion" is just wrong. "It is completion" is not the intent of the sentence.
It seems really important to me, that you get these sorts of things right in all your posts, even if you yourself won't be writing your prospective clients' blog posts.