Just remember, you won't have a buddy around to assist you in any way, so you really need to be comfortable taking care of problems.
For example, a broken mask strap or dislodged mask that plummets down to the bottom and away from your reach should be "no big deal".
You need to be weighted such that a catastrophic failure of your BCD isn't a problem.
If for some reason you get hung up on some leftover fishline or mono gillnet, you need to stay calm, stop moving, and slowly extricate yourself. (Whipping out the knife or shears is only done if you can't unhook yourself).
A tank falling out of the cambands shouldn't get you excited. You should be able to just remove the BCD, reinstall the tank and tighten up the bands.
And .... well by now you should be filling the blanks with all of the things that can and will go wrong that you must be able to deal with on your own. The problem of an inexperienced diver going solo is that you may not be ready to handle everything on your own, and even more likely, you may not truly understand the various risk associated with the particular dive and dive site.
The final item is something that you won't be able to deal with ---- if you have a severe medical problem such as loss of conciousness, epileptic seizure, injury from wildlife, cardiac problem, or anything else that prevents you from getting back to shore, there won't be a buddy to help you.
Understand the risks. Minimize the ones that you can minimize. Analyze the remaining risks and determine if they are acceptable.
Charlie Allen
p.s. About half of my dives are solo, using the same single tank setup that I use for buddied dives. My primary reason for solo diving is that I do lots of dives on the spur of the moment --- 30 minutes from sitting on my condo lanai in Maui and deciding to go diving until splashing in at the local reefs. I have never run out of air in 600+ dives, but have done a practice swimming emergency ascent simulating OOA from 90'. My wife knows where I'm diving, and at what time to call the Coast Guard for rescue or body recovery.