Will start by concurring with
@mdd1963. Simply put if your hardware is not up to the specifications required by any given game then the game will not play well.
Most games list three sets of specifications: minimal, recommended, and best. You do not want minimal and you do want as much "best" as you can afford.
Compare game hardware requirements to your computer's current hardware configuration. May be a bit difficult to do. (More on that to follow.)
Your post:
1) You are welcome. And do pay attention to other posts and suggestions. Others will try to help and I have no problem with that.
2) Do not put yourself at a disadvantage because you are only 15. That will pass - for better or worse.
There is no better time to start learning and I will submit that a good gamer who learns about hardware, software, and troubleshooting will become a better gamer. And probably will have more fun overall.
I.e.; Learn about your computer.
In the lower left screen corner is a box that reads "Type here to search". Type in "Task Manager" to start with. Explore the screens, windows, and tabs that appear. Do not change anything. Do the same with respect to two other built-in tools: "Resource Monitor" and "Reliability History".
You will find a whole new world with respect to computers and certainly more challenging than many games.
Backups.
Most people use computers for work and school purposes. All that work is saved on the computer. If the computer or some component is damaged all that work is often lost. To protect against data loss backup copies of that data are made and saved to other media, computers, or somewhere in the cloud. Multiple copies in different locations is advised.
Having backups makes it easier to recover and restore a computer to its original working condition once the failed components are fixed.
However, a hardware failure is not always the cause. User errors (very common), malware, viruses, and corrupted software can likewise wipe out everything important to you that is on your computer. Photos, music, videos, homework.....
Lots of online tutorials regarding how to do backups and recoveries. Read some of those and protect your work and data accordingly.
Should be a priority at all times but even more so when signs of a problem appear.