Craft and hobby shops or on line. What stores do you have available to you?
Amazon has a good selection, arts and craft stores too.
Or, if you have one from a coloring book you could make your own template or pattern on a thin sheet of plastic.
What you can do is place the picture under the transparent or semi transparent plastic sheet and trace it on the plastic with your choice of instruments...pencil,
sharpie marker, ink. Whichever works. Then you cut out the parts where you will stencil with an exacto knife or an single edged razor blade.
Hope this helps you.
Hi! Take a look at these:
I like ordering stencils from Royal Design Studios and Cutting Edge Stencils. The stencils are nice and thick.
I agree with Cutting Edge Stencils online. I’ve used several of theirs and they’re great quality. Here’s what came up when I searched “bird” on their site https://www.cuttingedgestencils.com/catalogsearch/result/?q=Bird