Daycamp Backdrop

I am making a backdrop for a daycamp and I wanted to know how I can tell if the backdrop will be clear when it prints?
And what program would work best for a backdrop with large dimensions?

I just did something like this…
i used photoshop and made the canvas size the size i needed, i made sure everything was smart objects so it wont be pixelated. when i was ready to print i flattened the layers and made the image size half. you tell the printing place to blow it up. save it as a pdf. i was also nervous that it will be pixelated but B"H it wasn’t!