Getting the check engine light to go away is easy - you can just have the bulb removed. But the check engine light isn’t your problem.
Since so much of your car’s operation depends on its computer the computer spends a bunch of its time checking up on different systems. It also requires certain info from other systems in order to do what it needs to do. When it detects problems it sets error codes and turns on the check engine light. This means that there is a problem and no good mechanic will tell you to ignore it.
At this point in time you have been ignoring it for so long (along with who knows what else) that helping you sort it all out by internet is probably impossible.
However, if you do want to give it a whirl then start by getting and reporting the exact error codes that are stored in the computer. They look like “P1234” - there are hundreds of these things, and normally multiple codes for the same systems. So referring to something like an O2 sensor or evap canister doesn’t help.