I need help with uv editor I want to create a texture on a plane but after creating a second uv map for the other side idk how to scale it right. The back texture is on the same image also. i need to know how i can make it fit.

This is the texture https://www.textures.com/download/3datlas0401/138065?q=Nettle

and here is my file: https://ufile.io/p5ztw7p0 

sorry for my bad english
I'm not 100% sure what the question is, but give this solution a try.

Go into edit mode, select all the vertices of your mesh with the A key, split the view to where you have a uv editor window, and the 3D view window, then, in the uv editor window, select all the vertices, s key to scale.

Hope it helps!