Welcome and your English is just fine...
Try to get Gimp and Inkscape as a raster and a vector drawing application.
Dungeonforge is a free stamp / icon based mapping tool which is useful to have
For 3D there is sketchup from google which a few people use and also Blender 3D which is a really powerful 3D app, free but real hard to get into if your brave.
Post some maps when you have some