First you need a object to use texture on. Create a new file, save with a reasonable name somewhere you can easily find it. Delete the cube and add/mesh/plane. Save again.
Go to context menu. Select material. Click new. Give it a logical name. Open the Surface tab, click the little circle on the right side of base color. Choose image texture. Click open image and find the image you want to use. I have placed the image file in a directory with the Blender file. Save again.
Render the image. Be proud of yourself!
P.S. Can`t find the image file? Try rendering as a one frame animation.