You can walk out Field lines rather easily—by using any orienteering compass. These align to the magnetic field of the Earth and let you walk in a fixed direction.
Miniaturise the compass and you can
walk out the field lines of a bar magnet. These spread out in all three dimensions. The Field lines of the Earth do as well that’s why compasses work almost everywhere on the globe, but as you’re walking the surface it’s not so easy to explore.
Just walking out the field lines is a kind of letting go: just keep walking in the direction of the needle. You have a choice, however—the needle has two ends: magnetic fields can push or pull. If you let go a stone it walks out the gravity field lines, always falling. There is no choice in how the field lines are walked. Gravity only pulls. Electrical field lines are more like magnetic field lines: there is a choice. Let an electrically charged object go and it walks out the field lines in one direction. Reverse the charge, and the direction walked out is reversed.