Probably the most important purely martial training that you should focus on while training solo is your footwork drills. Drill them drill them drill them.
Next would be any hand and foot etc patterns... in the air, on tires, on trees, on walls, on whatever. With and without stick(s.)
If there are several FMA schools in your town, then there are groups of people interested in training with you. You just need to find them. Many ways to do this, be creative. You dont even need to limit yourself to people who practice a FMA. There are often free "clubs" in big citys.
Then you can do all sorts of "non-martial" training... like pushups, situps, squats, jumping rope, wind sprints... the list here is almost endless.
