Connecting SAP to remote webservices using cURL
I'm not sure if you'll like this answer, but I'll write it anyway. :-)
If "webservice" means SOAP/WSDL for you, then it should be technically possible to generate some proxies to facilitate communication with your application. If you're talking about REST or some home-brewn stuff, it's a bit more work, but it's still possible. There's an example available in the SAP help portal. (And by the way, "some language" means ABAP.)
HOWEVER: You will need someone with SAP experience in the area you're interested in (materials management, sales, whatever). And you'll probably need someone to code some bits and pieces in the SAP system to make the interface work OR your clients will need some kind of communication server (PI) in between OR both. Unless you've got a customer who will let you play and gain experience in their system, you'll also need a SAP installation to do this.
Unfortunately, the big picture might be even bigger than you imagine...
EDIT: If you want to get an idea of what ABAP is, this answer might be a starting point.