psychoward13: I've read complaints about keys and not getting stuff.
First of all, welcome.
Sachys already answered brilliantly so this is basically just additional information.
What you describe here is most likely CD key shops. CD keys are like serial numbers for games. Different platforms host games -- some notable are GOG, Steam, Epic Games, UPlay (Ubisoft), Origin (EA), XBox PC Beta (Microsoft). If you buy games from these places, you buy directly from the shop that also hosts the game. They are safe.
But as you can buy the game without adding it to your account, you can also just buy the key to unlock the game for your account. It is these keys that are being sold on different CD key shops. I will not name any shops, but you can recognise them when they have games with multiple platforms. If there is say, "totallylegitgamesthataredefinitelynotascam dot com" and you see next to the games symbols for Steam, Playstation Store, Epic and such, that shop is not hosting the games, only selling the keys you would redeem on the actual platforms. And yes, there are risks. Some even use those services for money laundering. Anyone can become a seller on those platforms so there can be keys bought with stolen credit cards and such.
They only shop where I buy games from, other than directly from the shop that hosts the game, is Humble Bundle. Humble Bundle is charity and they get the keys themselves. That makes Humble Bundle a safe option, too.
GOG has also limitations for buying gift versions of games. You can buy only one copy of a game per day so those who bulk buy CD keys with stolen credit cards do not bother with GOG.
GOG is different in other ways, too. You do not need a separate launcher if you so choose. Steam, Epic Games, XBox PC and others require the launcher and live internet connection for their DRM. GOG is DRM-free and as such you can just download the installer files. They work like the CD-ROMs you are accustomed to. The difference is the files are downloaded from GOG to your hard drive and you launch the installer from there. You could burn them on CDs if you want, but I don't know many modern big titles that would fit on a CD. I have an external hard drive for the offline installers.
But I still use the GOG's own launcher, GOG Galaxy 2.0. I like it. I recommend it. Makes installing and maintaining installations easy. I also have many games from different platforms and GOG Galaxy 2.0 allows you to link all your other accounts to it so you can see everything in one launcher. You can also use it to download the offline installers or even shop for more games. But it's up to you. It is optional so you don't have to use it. I don't know any other platform that gives you this option -- or more specifically, allows you to opt-out of the launcher.
https://www.gog.com/galaxy From all the platforms out there, the biggest ones for PC are GOG, Steam, Epic Games and XBox. GOG is the most reliable in my opinion and has no DRM. However, this no DRM policy also limits the variety slightly. Not every game publisher is ok with the no DRM policy.
Anyway, welcome again. Like Sachys said there are free games here you could try. That way you can see how everything works. Here are more free games:
https://www.gog.com/games?page=1&sort=popularity&price=free And a lot of games are constantly on sale. Regular ones are weekend sales and midweek sales, then there are game/publisher specific sales, there are seasonal sales (summer sales, black friday sales...) so if you are looking for games on a budget, wait for sales. Build up your wishlist. Currently there's for example Fallout sales going on.
https://www.gog.com/promo/fallout_bombs_drop Still for the next 26 hours.
There's also a giveaway thread, but you need to be an active member of these forums to qualify. What means an active member? You have to be part of a few discussions within the last month. So come to game specific topics and discuss your favourite games for a month and then you can request games that are listed here:
https://www.gog.com/forum/general/the_community_giveaway_gog_edition_redux