To be honest without at least 1 good training partner or coach to at least hold mitts for you and do interaction drills with you it's going to be very difficult for you to learn things like how to control distance and set-point, rhythm, defensive and offensive timing, judgement, implication of different strategies to deal with different types of opponents, and a whole bunch of other skills and attributes that pretty much depend on interacting with another thinking breathing opponent.
Now, once you had enough experience and had already built those attributes and skills it is possible to refine them and work on them with supplementary drills, but learning them in the first place is going to be tough. It'd be like trying to design drills to teach you how to swim without having access to a pool or body of water.
So for now I would really just try to work on your fundamentals:
1) Solid fundamental fighting position and maintaining it as much as possible at all times (there are of course instances or circumstances where you would alter it, but don't worry about those yet)
2) Footwork- learn to move forward, backward, sideways, angularly, circularly, pivot, and switch step in any order while maintaining your effective fighting position as much as possible at all times
3) Striking mechanics- really work on the mechanics of throwing your basic strikes (whether that just be punches, or also kicks, knees, elbows, headbutts, forearm strikes, etc...since you didn't specify what type of sparring you were doing) so that you maximize efficiency, maintain a good defensive position while striking, maintain your balance at all times, return to your fighting position upon completing a punch/combination and don't drop your hands or leave your hands out away from your head, and can throw strikes in combination
4) Practice all of your combinations (whether hitting a bag or shadow boxing) with entering/penetration footwork and techniques (like a jab), and finish all of them with clearing footwork and techniques (like a bump or cut kick). This will build good habits that will eventually translate to sparring when you get the chance to do so
5) Practice all of your bag work and shadow fighting with constant and varied rhythm; in other words you should always seek to be moving your head, feet, body, faking/feinting strikes, or throwing strikes and changing the order and speed at which you do so
None of these can replace sparring, interaction drills, or good mitt work, but as far as solo drills they will go a long way to helping you build a good foundation. Good luck