Interface Guidance and Opinions Needed

Hello to all,

This is my first time posting to this forum and I am very new to
PostgreSQL. I am very excited about using it. I have set up a database
and just need a point in the right direction on interfacing. I have an
orders and messages database. One of the providers I would like to
interface with has sent me an XML spec to make HTTPS posts to. I am
just wondering what would be the easiest thing to use to implement the
two. I would like to scan my database for new orders then do an HTTPS
post to the provider. I would also like to periodically check for new
orders/messages from the provider via an HTTPS post and bring them into
my database (a constant exchange of information). I am wondering if
something like PHP would be a universal solution, or something similar?

Sorry if the information I have given is basic, I have been doing
research on the internet trying to figure out which direction to go and
starting off is a little overwhelming.

Thanks in advance for any information

Chris Golden