A good solo course should focus on teaching you how to independently plan and execute a solo dive safely including:
- Dive planning - objectives, navigation, entry/exit, anticipation of potential issues
- Gas planning and management - how much, what kinds, redundancy
- Execution - all aspects of independently (ie without assistance) executing a dive safely
- Equipment requirements - how to carry what you need with an appropriate amount of redundancy without becoming a Christmas tree
- Self rescue planning - planning for and being equipped to deal with any likely emergency (entanglement, getting lost, physical issues that may arise during the dive, etc)
- What types of dives should NOT be attempted solo
Be prepared to learn all of the above. Read as much as you can in this forum, keep an open mind and be prepared to learn.
I'm sure I'm missing some things but that is what comes to mind.