The Olyumpus OM10 is a nice camera to learn with BUT...There are very few lens choices for it, even used, and they are going to discontinue making parts for all their SLR film cameras. If you want an older manual camera I would suggest something from Canon, Nikon, Minolta or Pentax with plenty of lenses available on the used market. Nikon and Minolta have new manual cameras and lenses available.
The Oly OM-10 is the same camera as the Nikon FM-10, a Vivitar model, and I've seen a few other brand names slapped on the same body. The only real difference is the type of lens mount.
This camera is your low end inexpensively made 35mm SLR. The light meter sucks, at least compared to light meters built after 1985. Can you take fantastic photos with it? Absolutely, it's less the equipment and more the photographer.
But, for the same money you can probably get a Pentax ZX-M, which has a few modern features, including a nice light meter. And over 30 years with the same lens mount so Pentax lenses from 1970 to now fit on it.
Or spend half the money or less on a used older model metal mechanical SLR with pretty much the same features.