RPG

The OSRIC rules are free, and there's a couple of youtube channels that specialize in showing people how to solo rpg various systems. There are also plenty of tables where you could randomly build a dungeon, or an adventure. Check out all of the offerings at https://donjon.bin.sh . You could practically generate an entire random adventure there and then take some characters you control through it. That's what I would recommend looking at.

This is not for solo players, but Fiasco is amazing as an introduction to the idea of role-playing. Rules are incredibly light, once you understand them it takes like 10 minutes to explain it to new players, and a whole game start to end lasts maybe 1-2 hours.

It's basically babby's first RPG.

My favorite currently is Basic Fantasy. But I don't know how well it is for solo play. One where the core rules are free and which has solo play is Ironsworn.

Edit: If you search the Basic Fantasy Forums you'll find quite a lot of solo stuff as it seems. For example: https://www.basicfantasy.org/forums/viewtopic.php?t=4093

It depends on the amount of roleplay vs journaling you would like to try. My first try was with D100 and Four against the Darkness, but they were closer to a boardgame from my point of view. After that I tried Scarlet Heroes, one of the best solo rules and tables to play any classic DND game. Or anything, the tables and oracles can be used in a lot of different games. Now, the standard suggestion is Ironsworn because it's great and easy to play (although the book is big, everything is variations of one move). OH, did I mention it's free?

And then you can find Mythic GME 2ed, probably the best tool available to play any TTRPG solo. It's really worth it, but there are others easier to understand (I'd suggest One Page Solo Engine).

It depends on what you'd like to play: What setting? Where would you put the focus? More throwing dice? More journaling? Adventures? Epic fantasy? Sci-fi?

Cairn (https://cairnrpg.com/) is free and fairly simple. I play it solo sometimes, though the rules don't give any particular guidance for that, though someone has made a third party set of solo rules: https://manadawnttg.itch.io/barrow-delver

I've had some luck finding people online to play with, usually over discord, which is also an option.

https://lemmy.ml/c/solorpg

Bunch of stuff here.

Seems that what you're looking for is Ironsworn, it's a free, rules lite RPG that can be played Solo. I love it and it's sci-fi counterpart (Starforged) and there's also a pirate one in the making.

Also not free (DnD also isn't) but you can take a look at Dungeon World it's based on Apocalypse world so it's more RP friendly and can be very easy for newcomers because it's much more rules lite than DnD. Personally one of my favorite systems for medieval fantasy, but I don't really like DnD so this might not be what you're looking for. To play solo you might need this supplement though I've never used it.

I understand your situation, but my first recommendation would be to take another look at "that online stuff" - some groups are very supportive for beginners, some ways of playing (e.g. pbp) are easier if you are still learning and/or find playing over video/audio too stressful, or don't have much time, etc. The social element and collective creativity of playing in a group is part of what makes RPGs fun.

However, there are hacks for solo play for several great systems (although not free). For Blades in the Dark (the system I'm currently playing most) both Alone In The Dark (https://www.drivethrurpg.com/m/product/282013) and Omens in the Dark (https://guimonocores.itch.io/omens-in-the-dark) have been recommended to me, and the BitD Discord server is very friendly if you have any questions.