So I have searched quite a bit on google and youtube, but I think due to naming I cannot find the right info.
I found a lot of videos on how to make a minimap, but I don’t want to use a minimap. I only want to create your typical ‘Press M for map’ type of world/area map. Can I create this in a similar way to a minimap or is it completely different? If someone could help me, explain it to me, or link me a video or page where this is well explained (and up to date to 4.15 or at least compatible) that would be great 
(I’m working with BP)
If you want a 2d map, use a widget. You can nest a canvas inside another canvas - this will allow you to zoom in and drag it around with the mouse (optional if you do not wish to pan around or zoom). This will also allow you to add additional widgets that serve as points of interest, markers, notes, and so on.
- start by creating a widget with the canvas and the map image
- add functionality toggle allowing for show/hide when pressing M
- create separate widgets for markers and functions to add/edit/remove them (you can use an Overlay widget to handle these as a separate layer or the Canvas Panel to control Z draw order)
I think this should be a good starting point.
Its shown good at this tutorial, at 27 minute of video:
thats very helpfull, but can you explain how to synchronize with real 3d world ?, like if i click or make a markers in map ui widget, and thats show also in 3d real world exact location ?
Not sure what you mean. Translate screen coords to world?