concrete path running down center of garden...

[GinAndTings]

What can I do to make it look naice! Help!

paint it? stencils?
rip it out and replace with grass?
tile it?

Tile it or brick it or plant borders down either side to soften the edges – things like lavender spilling over onto the concrete would be nice.

Put some edging in either side and gravel it.

How wide is the path and who uses the garden? Children, pets, disabled people etc

Is it your own property op?
Concrete paths were often put down the middle so you had access to the washing line, which ran parallel to it. If you don't need it for that I would remove it. If you need a path at all, one down the side looks better and you don't get that 'garden cut in half' look.
Otherwise, you could create a planted border either side and even have a rose arch or two over it.
Or put in a very useful washing line (if there's not one there already).