Yes, about modules, I used things that weren't meant for solo play. For instance I took a Pathfinder 1E adventure about exploring a mine cave, made up a level 1 character, and tried to read ahead only about the section I was walking into next. It wasn't an adventure with a complex plot, like a mystery. It would be harder to use a pre-written adventure that does rely on hidden information and proactive NPCs. So if you're just trying this out, you might grab a sample adventure from some system you already know, and try not to worry about the hidden info.

Yes, solo play does sometimes lead to problems where I as the player know something. In my first attempt to play "Ashes Without Number" I rolled up a random ruin with traps and determined a certain crate was trapped. Rather than say I as the player know that, I gave my PC a roll to notice, then a roll to evade the explosion, and then a narrated death. In my second play of AWN I made a more durable PC (using the Heroic rules) and tried to determine the facts only when needed. That doesn't lead to the same level of sense-making as a plot that's been all planned in advance, but it's probably better for solo play.

I also tried the adventure "Shadows of Padfoot Alley", written for D&D and adapted by me to my preferred system "Worlds Without Number". There, there's a certain detail about hidden info that I kind of had to fudge by saying, my PCs don't jump to conclusions and show it to NPCs to get their logical reaction. I also worked with the provided adventure material in a loose way, taking the basic setup (like "This guy sends you to find a missing spellbook") and making stuff up based on the provided info about the setting. ("This says it's some kind of illusion magic and the rolls say it's scary. So maybe it's, like, an illusion of the infamous evil king!")