First off I have some questions for you. Do you have a shop or store nearby that has knowledgeable people on staff? Re-reading, obviously there's a shop near you since you ask about where to get the glass - that is part of the problem with today's e-commerce you can buy the product but there is no helpful guidance on how to use it. Do you know how to solder? Do you know how to cut glass? When I started I already knew how to solder and how to cut glass, so just the vague instructions from a shop wanting to sell me supplies and my willingness to experiment was all I needed to get started.
The glass in your picture looks to be just textured clear glass and should be available or able to be ordered from a regular glass shop - a place that sells replacement glass for home windows and mirror sheets and glass for table tops. These shops are fairly common here in the USA, but I don't know where you are.
Well looking back at what I've wrote I guess I have to say I'm sorry but it seems I don't have any really helpful guidance on how to get started. Having a shop nearby that offers some guided help on how to use their products will get you past the toughest hurdles. I've always wanted to take a class but that just hasn't happened. Mostly getting started it's just be willing to use some materials learning, playing and getting comfortable with the processes. YouTube and Google will be your friends and posting a question about a specific problem, might get you an answer you can work with. The active members here seem very knowledgeable and helpful.