For folks starting out? I wouldn't say that the "steps" should be specific systems, as that's travel and tourism. Instead, explore new places in the following regions:
- travel around inside the "extended bubble": the places where there are still plenty of non-procedural nebulae and stars (roughly 5-7 kly out, depending on direction)
- go above or below the plane to the edge, and beyond (via FSD boosts)
- head farther out from the extended bubble, and keep an eye out for exotic types of non-procedural stars (which are suppressed closer)
- visit the Core, especially Sagittarius A*, as it's the only body which is one of its kind
- while you're at the center, go as far above or below as you can, and marvel at the entire galaxy
- if you're in the area, pop by Jaques Station and say hello to Vitto Orbital
- go beyond Sag. A*, in whichever direction you'd prefer
- visit the edge of the galaxy (I'd recommend the South), the extreme edge if you can
- cross some sparse regions, inter-arm voids
I think that about sums it up. Then of course you can come up with specific stuff to look for, as noted above. The beauty of that is that you can come up with a lot of categories, even for a single type of body, like Jimbeau just illustrated.
