Most of the single use cameras are fairly wide angle - perhaps around 35mm so you will need a supplementary negative lens on the front to widen the view a bit.
When I was experimenting with the 65mm lens for my 6x12 camera I initially mounted it on an old 6x6 folder body (without the bellows or door). In order to get the viewfinder to show what the 65mm lens was presenting to the film I just taped a lens element from another viewfinder to the front.
If you know as much about optical theory as I do (almost none) then there is a lot of trial and error involved. It also helps if you have lots of spare parts from previous camera and lens repair attempts!