How can I make wall pictures with maps?

Do you mean just framing maps?

If you mean creating your own images using maps, I would decoupage. With a pencil lightly draw your image on your backing (canvas, wood, poster board...) Tear your maps into pieces and start applying with decoupage medium like mod podge or even a white glue and water mixture. For cleaner outer edges you can cut your paper to fit, but it's not really necessary. Easy to start images would be things like the Eiffel Tower, Washington Monument, Liberty Bell, etc. The possibilities are endless and using magazine pages would give your art color. Good Luck and Have Fun!

This has always been one of my favourite tutorials for this type of project:

https://www.sadieseasongoods.com/round-trip-oval-framed-vintage-road-maps/

Here's a few ideas for you. Have fun :)

https://www.pinterest.com/pin/106608716159056287/?lp=true