[AccessD] Hooking into APIs of supplemental vendors

When a company offers a service - in my case, the company I am dealing with
has offered to allow me to use their API to have my application submit MMS
and SMS messages - I get a sense that I am supposed, as a programmer, to
know how to make the features in their application(s) a part of the
program(s) I write. I know this happens all the time in the integrative
development marketplace, but since I have programmed in 95% VBA, I don't
really have the foggiest idea what they are talking about when they say "Our
API will do ______________ for you, feel free to download a free trial and
______________..." [get started using it??]

I assume maybe all their stuff is well documented, but I feel too slow and
stupid to understand documentation anymore and the "getting up to speed"
factor is in line with teaching an old dog new tricks. Are they simple
tricks? In other words, is this all supposed to be like plug and play
programming, or am I supposed to be learning entirely new platforms in order
to get acquainted with different vendors' functionality? I suppose maybe it
is a case by case thing?