I put an old Delta14" together from scratch, years ago. Coplanar was a straight edge and shims. The blade tracks in the middle of the tires and I often forget to lower tension.Completely apart is kind of open ended. Are the wheels installed and turning freely? Are whatever guides there are still installed? Is the tensioning spring in place? Or has the table been removed? A picture would give us more information. It is really rare for anyone to break down a band saw of any size or type.
If the wheels have been tinkered with, it gets really tricky to get it going again. If all that's installed, and there are tires on the wheels, try unplugging it, installing a blade and hand rotating the wheels per Snodgrass instructions. If the blade tracks OK, it might be pretty much OK. A 10 inch band saw is kind of light weight for some tasks, but really handy for quick and minor jobs. I keep a 14 inch Laguna for sizing lumber, but in the shop is a very similar small band saw that is really handy for small tasks.
Tensioning is something of an art. On my Laguna I pretty much go by the built-in gauge. But my little saw doesn't have one, so I tighten it until when I press with moderate pressure on the side of the blade, it deflects about a quarter inch. Sorry, that's about all there is to tensioning for me. The proof is in using the saw. Too much tension and the small blades fail, not enough and they don't cut vertically with accuracy. Big machines have tension relief levers, small ones require you release the tension manually. Don't let the saw sit for long under tension. Do make sure the blade is 90 to the table with a good triangle. The table rests on trunions, and to the inside of the blade, the table usually rests on a bolt so you can adjust using that until the blad is trued up. The final test for that is cut into a piece of wood, then flip it over and see if the blade goes right into the cut. If not, it's not 90 and will give you fits.
My small saw is a Rikon, but it looks like a very standard model with a 72.5 inch long blade. I suspect all of these come from the same factory.
Hopefully, the previous owner didn't mess with the co-planer adjustment of the bottom wheel in particular. That requires a high precision jig to set. It may take a mess of adjusting to fix this if the owner messed with it. If it's out the blade will drift forward and back or come off the wheel.
Hope this is useful.