Depending on what country you live in, you may be considered a legal adult, in which case you can go buy more and they technically can not stop you. Or you can move out entirely if it’s within your means.
On the other hand, if you don’t qualify as legal adult, and are not emancipated either, you’ll have to make do with the least expensive options.
If you have a computer, trawl itch .io and gamejolt for free games.(There’s also a ton of free Rpgmaker titles out there, and a few like Mad Father and The Witch’s House, are quite good.)
If you have a phone or tablet, see if you can find the handful of good titles on your respective appstore. (I’ve heard good things about Genshin Impact.)
On console, there’s usually bargain bins at the Target and similar stores where cheap deals can be had. I’ve seen PS3 games at both the Five Below and the Goodwill, as well as the occasional so you really never know when these things will pop up.
The virtual stores for consoles also have freebies and sales pretty frequently.
They also usually have services that provide more games- I know xbox has a pass or something, but I’m not familiar with it.
I can confirm that that the Nintendo Virtual Console on the Switch has a nice selection, though.
And there is emulation, but do keep in mind that emulation programs require a lot of processing power to function well, especially for emulations of games from newer consoles/handhelds or those with 3d graphics.
Speaking of handhelds, if you have a Ds or 3Ds, there are a ton of cheap GBA and Ds games on Ebay they can play.
There’s also the cheaply made bootleg, but nonetheless full functioning multicarts, which hold multiple games.
You can also find romhacks in cartridge form floating around Ebay as well. It’s kind of surreal.
Just make sure to keep track of your responsibilities once you’ve acquired your new games. It’s important to take of care of your life outside games.
Also, headphones are your friend.