Discussion of table top roleplaying games.
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
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'll second Ironsworn - it takes a little bit to figure out the mindset, but it's also improved my other games since I started playing it! And, yeah, Ironsworn is free!
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.
And in a lot of ways it's much more an RPG than D&D or Pathfinder because RPing is literally all you do. I've played 4 times now with different groups and it definitely makes a difference what people you play with but it hasn't been hard to convince them to try and most have enjoyed 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.
While not free, I just have to recommend Apocalypse World. Its rules are relatively simple (compared to DnD). I mention it because Apocalypse World was one of the inspirations for Blades in the Dark, which is also a great game!
Absolutely! Do you have a recommendation for a solo hack of AW?
Ironsworn (and it's sci-fi offshoot Starforged) are the only solo PbtA (Powered by the Apocalypse) games that I know of. They're fantastic, but a bit mind-bending if they're your first foray into the style of game. If you're interested, I'd recommend finding an actual play to see the game flow; the rules will make a lot more sense.
Apocalypse World is my all-time favorite RPG.
I enjoy other PbtA games, but Apocalypse World is the gold standard IMO.
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?
Man thanks until OP posted I had no clue you could play dnd on your own.
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.
Re: online, I agree it's not as good, but I encourage you to try to at least get some experience. Still fun. If you really can't stand Discord-type voice chat for some reason, there are still places that do play by forum. You'd have to search. You can also consider going to a convention tho ask someone how do you get a session seat (because GM shortage).
RPG folks tend to be friendly (more often than not...) and the more people you meet, the more chance you have of finding a group eventually if this is what you want.
Anyway, for solo I recommend Me Myself And Die and Geek Gamers as good sources of inspiration on YouTube. 3rd season MMAD features Dominion system which is free, but you have to add some special solo rules to it. You can search the GG channel for advice on homebrewing those. If you go solo there's even less reason for adapting to D&D monoculture.