The scale of atoms and galaxies is vastly different, so it's challenging to provide an exact distance for traveling from one galaxy to another if you were shrunk down to the size of an atom. However, let's explore a rough estimate to get a sense of the scale involved.
The size of an atom can vary depending on the element, but let's consider the typical size of a hydrogen atom, which is the simplest and most abundant element in the universe. The diameter of a hydrogen atom is roughly about 0.1 nanometers (1 × 10^(-10) meters).
On the other hand, galaxies can vary in size, but let's take the Milky Way galaxy, our own galaxy, as a reference. The Milky Way has a diameter of approximately 100,000 light-years, which is about 9.5 × 10^17 kilometers.
Now, let's assume we could linearly scale down the distance between atoms and galaxies. If we shrink the distance by a factor of 10^10, the atom would be scaled down to a distance of about 1 × 10^(-20) meters. Applying the same scaling to the diameter of the Milky Way, it would be reduced to roughly 9.5 × 10^7 kilometers.
Therefore, by this rough estimate, if you were shrunk down to the size of an atom and the distances were linearly scaled, you would still need to travel approximately 9.5 × 10^7 kilometers to reach another galaxy.
Keep in mind that this is a very simplified approximation, and in reality, the scales involved in the macroscopic world of galaxies and the microscopic world of atoms cannot be directly compared or scaled linearly. The nature of space and distance is different on these scales, and it's not feasible to physically travel from an atom to another galaxy in the way we usually think of travel.